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Fachbereich Informatik der Universität Hamburg RACE User's Guide

1. MS 6 BS gt Bottom Figure 9 The RACE main page DL notation Cy E amp RACE syntax Cy gt Co Examples Human gt Animal amp Biped mammal gt all has parent mammal some teaches Course gt Student amp some degree BS Prof For the users convenience RACE also supports another kind of concept axiom Concept equations state the equality between two concept terms DL notation Ci Co RACE syntax C1 C2 Examples Woman Human amp Female Primary Color amp Yellow Red Blue Actually a concept equation C1 Ca can be expressed by the two GCIs C E C2 and Ca E C1 Concept axioms are separated by a dot 59 C 2 3 Concept Terms There are two predefined concepts in RACE The concept top denotes the most general concept and the concept bottom denotes the inconsistent concept Besides concept names the following terms are also concept terms Boolean terms build concepts by using the boolean operators DL notation RACE syntax Negation a C Conjunction Cn D C amp D Disjunction CuUD CID Example Tree Plant Graph amp some contains Cycle Qualified restrictions state that role fillers have to be of a certain concept Value restic tions assure that the type of all role fillers is of the specified concept while exist restrictions require that there be a filler of that role which is an instance of the specified concept DL notation RACE syntax
2. define primitive concept Grandmother and Mother Female define primitive concept Father Parent 20 define concept KRSS macro Description Defines a concept Syntax define concept CN C Arguments CN concept name C concept term Remarks Please note that in RACE definitions of a concept do not have to be unique Several definitions may be given for the same concept Examples define concept Grandmother and Mother some has child Parent define disjoint primitive concept KRSS macro Description This axiom states the disjointness of a group of concepts Syntax define disjoint primitive concept CN GNL C Arguments CN concept name GNL group name list which list all groups to which CN belongs to among other concepts All elements of each group are declared to be disjoint C concept term that is implied by CN Remarks This function is just supplied to be compatible with the KRSS Examples define disjoint primitive concept January Month exactly 31 has days define disjoint primitive concept February Month and at least 28 has days at most 29 has days 21 add concept axiom function Description This function adds a concept axiom to a TBox Syntax add concept axiom tbox C C2 amp key inclusion p t Arguments tbor TBox object Ci C2 concept term inclusion p boolean indicating if the concept axiom is an inclusion axiom GCI or an equality axiom The default is to state an inclusi
3. Exists restriction J R C some R C Value restriction VRC all RC Example human all has ancestors human Number restrictions can specify a lower and upper bound for the number of role fillers each instance of this concept has for a certain role DL notation RACE syntax At most restriction lt nR at most n R At least restriction gt n R at least n R Example Week at most 7 has days amp at least 7 has days The precedence of the operators is amp gt The comment sign is after this sign the rest of the line is ignored The RACE system is not case sensitive Concepts may be put in parentheses C 2 4 Role Declarations As we have seen before in RACE the set of roles R consists of primitive roles transitive roles and features The features and transitive roles have to be declared In the following R possibly with index denotes a role name Feature declaration Features also called Attributes restrict a role to be a functional role That means each individual can only have up to one filler for this role RACE syntax feature R Example feature has mother Transitive Role declaration states that a role is transitively closed Please note that the transitive roles cannot be used in number restrictions and that features can not be transitive 60 RACE syntax transitive R Example transitive ancestor of Besides these kinds of special roles role hierarchies can be established C
4. in knowledge base family smith family 54 signature atomic concepts person human female male woman man parent mother father grandmother aunt uncle sister brother roles has descendant transitive t has child parent has descendant has sibling has sister parent has sibling has brother parent has sibling has gender feature t individuals alice betty charles doris eve 335 domain range restrictions for roles implies top all has child person implies some has child top parent implies some has sibling top or sister brother implies top all has sibling or sister brother implies top all has sister some has gender female implies top all has brother some has gender male 333 the concepts implies person and human some has gender or female male disjoint female male implies woman and person some has gender female implies man and person some has gender male equivalent parent and person some has child person equivalent mother and woman parent equivalent father and man parent equivalent grandmother and mother some has child some has child person equivalent aunt and woman some has sibling parent equivalent uncle and man some has sibling parent equivalent brother and man some has sibling person equivalent sister and woman some has sibling person 335 Alice is the mother of Betty and Charles instance
5. individual types ica o Bere A INSLANLTALOTS 2 800 fee e i a e e A Be ee lv 37 38 38 38 38 39 39 39 40 40 40 41 41 41 41 42 42 42 43 43 43 44 44 44 44 45 45 45 45 46 46 46 46 47 47 47 47 concept instances 25 soe A a een Ad er retrieve concept instances individual fillers 2 2 2 fae La RE ah retrieve individual fillers retrieve related individuals retrieve individual relations retrieve direct predecessorS o loop over aboxes per Cum all abs u a Ste an Da Mie ne ee a a ts alilsindividual ss e GALS ee A Re a Ga ar A all concept assertions for individual all role assertions for individual in domain all role assertions for individual in range all gt concept assert ons in su like besa Boe i deo a Tea all role aSS 6rtions oo a ee aa p e ee a deSCribe abow 2 2 a ea a en a an Dect describe individual s ss m ox 2 08 2 82 8 28 a a a eh A KRSS Sample Knowledge Base Al A 2 KRSS Sample T BOX sr 2 2 wu ne ae KRSS Sample ABOX po a 2 2 24 wu be eb a mare ee eee a a B Integrated Sample Knowledge Base C Web Interface Cl C 2 Introduction 2 2 Aa 22 AAA AA Ore hn AR a he How to use the interface 2 CE ee C 2 1 Register asa new user o oo e 0 2 2 Concept AXIOMS re se a es EB ee Dee ek
6. tbox TBox object List of role names 43 role parents KRSS macro Description Gets the roles from the TBox that directly subsume the given role in the role hierarchy Syntax role parents RN optional TBN tbox name current tbox Arguments RN role name TBN TBox name Values List of role names atomic role parents function Description Gets the roles from the TBox that directly subsume the given role in the role hierarchy Syntax atomic role parents RN tbox Arguments RN role name tbor TBox object Values List of role names loop over tboxes function Description Iterator function for all TBoxes Syntax loop over tboxes tbox variable loop clause Arguments tbox variable variable for a TBox object loop clause loop clause all tboxes function Description Returns all TBoxes Syntax all tboxes Values List of TBox objects 44 all atomic concepts Description Syntax Arguments Values Remarks all roles Description Syntax Arguments Values Examples all features Description Syntax Arguments Values all transitive roles Description Syntax Arguments Values Junction Returns all atomic concepts from the specified TBox all atomic concepts amp optional tbor current tbox tbox TBox object List of concept names all atomic concepts find tbox my tbox Junction Returns all roles and features from
7. top bottom not C and C1 Cp or Cy Cn some RN C all RN C at least n RN at most n RN exactly n RN Figure 4 RACE concept terms Boolean terms build concepts by using the boolean operators DL notation RACE syntax Negation C not C Conjunction C10 MC and Ci Cn Disjunction C LU UC or Cy Cn Qualified restrictions state that role fillers have to be of a certain concept Value restric tions assure that the type of all role fillers is of the specified concept while exist restrictions require that there be a filler of that role which is an instance of the specified concept DL notation RACE syntax Exists restriction 3RN C some RN C Value restriction Y RN C all RN C Number restrictions can specify a lower bound an upper bound or an exact number for the amount of role fillers each instance of this concept has for a certain role Only roles that The signature does not have to be specified explicitly in RACE knowledge bases the system can compute it from the all the used names in the knowledge base but specifying a signature may help avoiding errors caused by typos are not transitive and do not have any transitive subroles are allowed in number restrictions see also the comments in Horrocks et al 99a Horrocks et al 99b DL notation RACE syntax n RN at most n RN n RN at least n RN n RN exactly n RN At most restri
8. Syntax tbox name thor Arguments thor TBox object Values TBox name 4 2 ABox Management in abox macro Description The ABox with this name is taken or generated and bound to current abox If a TBox is specified the ABox is also initialized Syntax in abox ABN amp optional TBN tbox name current tbox Arguments ABN ABox name TBN name of the TBox to be associated with the ABox Remarks If the specified TBox does not exist an error is signalled function Usually this macro is used at top of a file containing an ABox This macro can also be used to create new ABoxes 14 Examples See also init abox Description The specified ABox is the current abox until in abox is called again or the variable current abox is manipulated directly The TBox of the ABox is made the current tbox in abox peanuts characters peanuts instance Schroeder Piano Player Macro signature on page 11 function Initializes an existing ABox or generates a new ABox and binds it to the variable current abox During the initialization all assertions and the link to the referenced TBox are deleted Syntax init abox abox amp optional tbox current tbox class standard abox Arguments abor ABox object to initialize tbor TBox object associated with the ABox class class of the new ABox object that must inherit from the class standard abox Values ABox object Remarks The tbox has to already exist before
9. function Checks if the two concepts are equivalent in the given TBox concept equivalent p C C2 tbox C1 C2 concept terms tbor TBox object Returns t if C and C are equivalent concepts in tbor and nil otherwise For testing whether two concept terms are equivalent with respect to a TBoz the first argument must be a TBox If the equality is to be tested without reference to a TBox nil can be used Function atomic concept synonyms on page 39 30 concept disjoint macro Description Checks if the two concepts are disjoint e g no individual can be an instance of both concepts Syntax concept disjoint C1 Ca amp optional tbor current tbox Arguments Ci C2 concept term tbor TBox object Values Returns t if C and Cs are disjoint with respect to tbox and nil otherwise Remarks For testing whether two concept terms are disjoint with respect to a TBoz the third argument must be a TBox If the disjointness is to be tested without reference to a TBox nil can be used concept disjoint p Junction Description Checks if the two concepts are disjoint e g no individual can be an instance of both concepts Syntax concept disjoint p C C2 tbox Arguments Ci C2 concept term tbor TBox object Values Returns t if C and C are disjoint with respect to tbox and nil otherwise Remarks For testing whether two concept terms are disjoint with respect to a TBoz the third argument must be a TBox If the dis
10. individual p 38 individual types 47 individuals related p 37 individuals related 36 inference modes 9 init abox 15 init tbox 11 instance 24 instantiators 47 load ABox 16 load TBox 13 loop over aboxes 50 loop over tboxes 44 most specific instantiators 47 name set 38 number restriction 7 primitive concept 7 range restriction 9 realize abox 35 related 26 rename ABox 17 rename TBox 14 retraction 10 retrieve concept instances 48 retrieve direct predecessors 50 66 retrieve individual fillers 49 retrieve individual relations 49 retrieve related individuals 49 role hierarchy 8 role ancestors 42 role children 43 role descendants 42 role offspring 43 role p 32 role parents 44 role subsumes p 32 role subsumes 32 save abox 17 save tbox 13 signature 6 signature 12 state 27 subrole 22 23 superrole 22 23 taxonomy 38 tbox 18 tbox classified p 34 tbox coherent p 34 tbox name 14 top 18 transitive role 8 22 transitive p 33 unique name assumption 9 value restriction 6
11. 11 function Generates a new TBox or initializes an existing TBox and binds it to the vari able current tbox During the initialization all user defined concept ax ioms and role declarations are deleted only the concepts top and bottom remain in the TBox init tbox thor amp optional class tbox tbor TBox object class class inheriting from the class tbox tbox This is the way to create a new TBox object 11 signature Description Syntax Arguments Remarks Examples See also macro Defines the signature for a knowledge base If the keywords atomic concepts and roles are used The current tbox is initial ized and the signature is defined for it If the keyword individualnames is used the current abox is initialized If all key words are used the current abox and its TBox are both initialized signature amp key atomic concepts nil roles nil individuals nil atomic concepts is a list of all the concept names specifying C roles is a list of all role declarations thereby also specifying R individuals is a list of individual names specifying Z Usually this macro is used at top of a file directly after the macro in knowledge base in tbox or in abox Actually it is not necessary in RACE to specify the signature but it helps to avoid errors due to typos Signature for a TBox signature atomic concepts Character Baseball Player roles has p
12. CN amp optional thor current tbox CN tbox concept name TBox object Returns t if CN is aname of a concept and nil otherwise Junction Checks if RN is a role name for a role in the specified TBox role p RN amp optional tbox current tbox RN tbox role name TBox object Returns t if RN is a name of a role and nil otherwise 32 transitive p Description Syntax Arguments Values feature p Description Syntax Arguments Values 7 3 TBox classify tbox Description Syntax Arguments Remarks Junction Checks if RN is a transitive role in the specified TBox transitive p RN amp optional tbor current tbox RN role name tbox TBox object Returns t if the role RN is transitive in thor and nil otherwise function Checks if RN is a feature in the specified TBox feature p RN amp optional tbox current tbox RN role name tbor TBox object Returns t if the role RN is a feature in thor and nil otherwise Evaluation Functions Junction Classifies the whole TBox classify tbox amp optional tbox current tbox tbox TBox object This function needs to be executed before queries can be posed 33 check tbox coherence function Description Syntax Arguments Values Remarks This function checks if there are any unsatisfiable atomic concepts in the given TBox check tbox coherence amp optional tbox current tbox tbox
13. In the lazy mode of inference the default RACE avoids computations that are not required concerning the current query In some situations however in order to globally minimize processing time it might be better to just classify a TBox before answering a query eager inference mode The inference behavior of RACE can be controlled by setting the value of the variables auto classify and auto realize for TBox and ABox inference respectively The lazy inference mode is activated by setting the variables to the keyword lazy Eager inference behavior can be enforced by setting the variables to eager The default value for each variable is lazy verbose which means that RACE prints a progress bar in order to indicate the state of the current inference activity if it might take some time If you want this for eager inferences use the value eager verbose If other values are encountered the user is responsible for calling necessary setup functions not recommended We recommend that TBoxes and ABoxes should be kept in separated files If an ABox is revised by reloading or reevaluating a file there is no need to recompute anything for the TBox However if the TBox is placed in the same file reevaluating a file presumably causes the TBox to be reinitialized and the axioms to be declared again Thus in order to answer an ABox query recomputations concerning the TBox might be necessary So if different ABoxes are to be tested they should pr
14. KRSS macro Gets all atomic concepts of a TBox which are subsumed by the specified concept concept descendants C amp optional TBN tbox name current tbox C TBN concept term TBox name List of name sets This macro is the transitive closure of the macro concept children 39 atomic concept descendants function Description Syntax Arguments Values Remarks Gets all atomic concepts of a TBox which are subsumed by the specified concept atomic concept descendants C tbox C concept term tbor TBox object List of name sets This function is the transitive closure of the function atomic concept children concept ancestors KRSS macro Description Syntax Arguments Values Remarks Gets all atomic concepts of a TBox which are subsuming the specified con cept concept ancestors C amp optional TBN tbox name current tbox C concept term TBN TBox name List of name sets This macro is the transitive closure of the macro concept parents atomic concept ancestors function Description Syntax Arguments Values Remarks Gets all atomic concepts of a TBox which are subsuming the specified con cept atomic concept ancestors C thor C concept term tbor TBox object List of name sets This function is the transitive closure of the function atomic concept parents 40 concept children KRSS macro Description Gets the dire
15. TBox object Returns a list of all atomic concepts in tbox that are not satisfiable i e an empty list NIL indicates that there is no additional synonym to bottom This function does not compute the concept hierarchy It is much faster than classify tbox so whenever it is sufficient for your application use check tbox coherent This function is supplied in order to check whether an atomic concept is satisfiable during the development phase of a TBox There is no need to call the function check tbox coherent if for instance a certain ABox is to be checked for consistency with abox consistent p tbox classified p function Description Syntax Arguments Values It is checked if the specified TBox has already been classified tbox classified p tbox tbox TBox object Returns t iff the specified TBox has been classified otherwise it returns nil tbox coherent p function Description Syntax Arguments Values Remarks This function checks if there are any unsatisfiable atomic concepts in the given TBox tbox coherent p tbox tbox TBox object Returns t if there is an inconsistent atomic concept otherwise it returns nil This function calls check tbox coherence if necessary 7 4 ABox Evaluation Functions 34 realize abox Description Syntax Arguments Values Remarks abox realized p Description Syntax Arguments Values Junction This function checks the consistency of t
16. be used in number restrictions define primitive role conjunctive role parents R 1 R n define primitive role has descendant transitive t parent has child Macro signature on page 11 Section 3 3 and Figure 6 on page 9 for domain and range restrictions define primitive attribute KRSS macro with changes Description Syntax Arguments Remarks Defines an attribute define primitive attribute AN amp key parents nil AN attribute name parents provides a list of superroles for the new role The role AN has no superroles if parents is bound to nil If only a single superrole is specified the keyword parent may alternatively be used see examples This macro is supplied to be compatible with the KRSS specification it is redundant to the use of macro define primitive role with feature t This function combines several KRSS functions for defining properties of an attribute 23 An attribute cannot be transitive A role with a feature as a parent has to be a feature itself Examples define primitive attribute has mother parents has parents define primitive attribute has best friend parent has friends See also Macro signature on page 11 Section 3 3 and Figure 6 on page 9 for domain and range restrictions add role axiom function Description Adds a role to a TBox Syntax add role axiom thor RN key transitive nil feature nil parents nil Arguments thor TBox object to
17. di a forget role assertion o define distinct individual 0 0 0 0 002082 2G 6 Reasoning Modes FAauUt0o lt Classifyk kogos fo hoe a ea dr auto realize 2 oca un na Ken nr ne 7 Evaluation Functions and Queries 7 1 7 2 7 3 7 4 7 8 Queries for Concept Terms concept satisfiable concept satisfiable p concept subsumes 2 2 Emmen concept equivalent P concept disjoint o concept dISJjoINt P s s chs ci eais soyo a ew gt alc concept coherent o Role Queries 2 nna see ghee Boe ee Ba dann TFoOLe SubSumMes efi 222 Be a la ERs TOA TUTOSD s io dae ee sk ee eee e ee TBox Evaluation Functions Cl ssity tboX s au ci pli ee eee pppd a pt check tbox coherence 0 tbox classified P o tbox coherent p ui a a is ABox Evaluation Functions realize abox 2 Coon abox realized P ABoX Queries u sia uh Boa Ba eh abox consistent P check abox coherence 2 nn individual instance individual instance p o o individuals related 0 0 individuals related p 2 individual equal u 8 2 E E E rn ii 28 28 28 28 28 29 29 29 30 30 30 31 31 31 32 32 32 32 32 3
18. find abox peanuts characters function Gets all pairs of individuals that are related via the specified relation retrieve related individuals RN abor abox RN ABox object role name List of pairs of individual names retrieve related individuals has pet find abox peanuts characters may yield Charlie Brown Snoopy John Arbuckle Garfield Function individuals related p on page 36 function This function gets all roles that hold between the specified pair of individu als retrieve individual relations IN IN abor IN individual name of the predecessor IN individual name of the role filler abox ABox object List of role names retrieve individual relations Charlie Brown Snoopy find abox peanuts characters Function individuals related p on page 36 49 retrieve direct predecessors function Description Gets all individuals that are predecessors of a role for a specified individual Syntax retrieve direct predecessors RN IN abox Arguments RN role name IN individual name of the role filler abox ABox object Values List of individual names Examples retrieve direct predecessors has pet Snoopy find abox peanuts characters loop over aboxes function Description Iterator function for all ABoxes Syntax loop over aboxes abox variable loop clause Arguments abox variable variable for a ABox object loop clause loop
19. in a TBox may also be arranged in a role hierarchy Features also called attributes restrict a role to be a functional role e g each individual can only have up to one filler for this role Transitive Roles are transitively closed roles If two pairs of individuals JN and IN 2 and IN and IN3 are related via a transitive role R then IN and IN3 are also related via R Role Hierarchies define super and subrole relationships between roles If R is a super role of Ra then for all pairs of individuals between which Ra holds R must hold too In the current implementation the specified superrole relations may not be cyclic If a role has a superrole its properties are not in every case inherited by the subrole The properties of a declared role induced by its superrole are shown in Figure 5 The table reads as follows For example if a role RN is declared as a simple role and it has a feature RN as a superrole then RN will be a feature itself Superrole RN RIRI F Subrole RN declared as element of Figure 5 Conflicting declared and inherited role properties The combination of a feature having a transitive superrole is not allowed and features cannot be transitive Note that transitive roles and roles with transitive subroles may not be used in number restrictions RACE does not support role terms as specified in the KRSS However a role being the conjunction of other roles can as well be expressed by usin
20. it can be referred to by init abox ensure abox signature function Description Defines the signature for an ABox and initializes the ABox Syntax ensure abox signature abor amp key individuals nil Arguments abor ABox object individuals is a list of individual names specifying Z See also Macro signature on page 11 is the macro counterpart It allows to specify a signature for an ABox and a TBox with one call 15 in knowledge base macro Description This form is an abbreviation for the sequence in tbox TBN in abox ABN TBN Syntax in knowledge base TBN ABN Arguments TBN TBox name ABN ABox name Examples in knowledge base peanuts peanuts characters current abox special variable Description The variable current abox refers to the current ABox object It is set by the function init abox or by the macro in abox 16 save abox function Description If a pathname is specified an ABox is saved to a file In case a stream is specified the ABox is written to the stream the stream must already be open Syntax save abox pathname or stream amp optional abor current abox amp key syntax krss transformed nil if exists supersede if does not exist create Arguments pathname or stream is the name of the file or an output stream abor ABox object syntax indicates the syntax of the ABox It might as well be names of other DL systems transformed if bound to t the ABox is sa
21. the filler RN role name abox For answering subsequent queries the index structures for the ABox will be recomputed i e some queries might take some time e g those queries that require the realization of the ABox forget role assertion find abox peanuts characters Charlie Brown Snoopy has pet forget role assertion find abox peanuts characters Lucy Linus has brother define distinct individual KRSS macro Description Syntax Arguments Values Remarks state Description Syntax Arguments Remarks This statement asserts that an individual is distinct to all other individuals in the ABox define distinct individual IN IN name of the individual IN Because the unique name assumption holds in RACE all individuals are distinct This function is supplied to be compatible with the KRSS specifi cation KRSS macro This macro asserts a set of ABox statements state amp body forms forms is a sequence of instance or related assertions This macro is supplied to be compatible with the KRSS specification It realizes an implicit progn for assertions 27 forget Description Syntax Arguments Remarks macro This macro retracts a set of ABox statements forget body forms forms is a sequence of instance or related assertions For answering subsequent queries the index structures for the ABox will be recomputed i e some queries might take some time
22. which the role is added RN role name transitive if bound to t declares that the role is transitive feature if bound to t declares that the new role is a feature if feature is bound to t parents providing a single role or a list of superroles for the new role The role RN has no superroles if parents is bound to nil Values tbox Remarks For each role RN there may be only one call to add role axiom per TBox See also Section 3 3 and Figure 6 on page 9 for domain and range restrictions 5 4 Assertions instance KRSS macro Description Builds a concept assertion asserts that an individual is an instance of a concept Syntax instance IN C Arguments IN individual name C concept term Examples instance Lucy Person instance Snoopy and Dog Cartoon Character 24 add concept assertion function Description Builds an assertion and adds it to an ABox Syntax add concept assertion abox IN C Arguments abor ABox object IN individual name C concept term Values abor Examples add concept assertion find abox peanuts characters Lucy Person add concept assertion find abox peanuts characters Snoopy and Dog Cartoon Character forget concept assertion function Description Retracts a concept assertion from an ABox Syntax forget concept assertion abox IN C Arguments abor ABox object IN individual name C concept term Values abox Remarks For answering subse
23. 2 5 Role Axioms Role Hierarchies consist of super and subrole relationships between roles If R is a superrole of Ro then for all pairs of individuals between which Ra holds R must hold too All subroles of a feature are implicitly declared as features Sub or superroles of a transitive role are not neccessarily transitive unless declared as being so RACE syntax parent Reup Rsuper Example parent is mother of is parent of C 2 6 Building an ABox In the ABox pane see Fig 9 assertions can be made about individuals It can be stated that an individual is an instance of a concept and that a relation between two individuals holds Concept assertions state that an individual is an instance of the specified concept C RACE syntax i C Role assertions state that an individual j is a role filler for a role R with respect to an individual 2 RACE syntax i j R C 2 7 Building and Executing a Query In the query field queries can be posed concering the TBox and the ABox Some example queries are shown in Fig 10 C 2 8 Queries concerning the concept hierarchy The following queries always refer to the current TBox implicitly They depend on set C of concept names extracted from the current TBox Superconcepts returns the most specific subsumers of CN found in C RACE syntax superconcepts CN Subconcepts returns the most specific subsumees of CN found in C RACE syntax subconcepts CN Equivalentp c
24. 3 33 33 33 34 34 34 34 35 35 35 35 35 36 36 36 37 37 individual not equal individual pis sam eor a e Bee thee Ste A 8 Retrieval 8 1 8 2 TBox Retrieval lt sss u 0 28 22 ee os Be ad ee TAXONOMY gt ran an ar E e EE ee ney goto le be re 4 concept synonyms s dco ea D ea aak e 0 00000 atomic concept synonyms concept descendants atomic concept descendants concept ancestors oo e see e ae Bae atomic concept ancestors 22 200 concept children 2 2 2 o atomic concept children concept parents soci ee oe De atomic concept parents 222 0 role descendants atomic role descendants TOoLEe ancestors ria u aa rn atomic role ancestors roteschitdren 2 sus Aig Boke ee a re atomic role children r Le parents un ee a ee atomic role parents o loop over tboxes o ALIS TDOXOS da Pia nn ea Des ale all atomic concepts all r t si nee ee all features all transitive roles describe tbok e 24 40 por ahy e a Bu a E e describe concept o describe role anarai aii P AA E A ABox Retrieval ua esi a el namen individual direct types most specific instantiators
25. Ask sii a Ate a Cet es OE Mea doh AS On OT 13 TIAS LOs en ee Gee a ee Get RE ea BN ee TN ee 14 4 27 ABox Management 2 2 dl Hase ri A Da in ADO sanieren ee a le A be ig et a ac a 1ATESADOX gt soured Are A et A A AS BE gas ensure abox signature KL I e in knowledge base e CUTTONEZADOX eii ae pi ee GE dee a Ge eae Saye ab s ynu laa Hegde Glin af Ge enna ed Akh Sd A Se delet ed find abor AA A ead a A A a tae O o e A to CONE ed he ke A ee i eR Th ga 5 Knowledge Base Declarations 5 1 Built in Concepts in a e a ee er Bee ee ry LOPE MEO clos ds e Bos oh FDOTEOME DOTTOM sono a a Oe ees 5 2 Concept AXIOMS ya asin eae a ee Ae Qe ee ch ia implies A che ee A Ad Ii Ws Slt ANA de EAD ES St ol Teich equivale alba ct a ey sd eg aa ESTORNE Ls a O a oT eRe e SM a a O ald 2 gt define primitive concept define concept x pae iie a a o ee eg define disjoint primitive concept aao add concept axiom urn ae an al ar ia E ed add disjointness axioM ee 5 3 Role Declarations ns ca a pes ir a ER Pe ee define primitive role 0 en define primitive attribute nun add roLe axioM sei g a al ee ee ER a 9 4 A Bor ates ANST ANC u ee a ee ee N NE bh ees add concept assertion forget concept assertion ee related 3 2 re aa ee A Sip Sb ee ces add rol e assertion ci be he A BE li he
26. C 2 3 Concept Terms fac hte ee BS oe oe A Ae ee Ein es C 2 4 Role Declarations 2 22 En nn G 2 52 Role Asionis 4 2 Te PY bate EA Se ee A 2 6 Buildingvan ABOX cds io geo Sep an Beg ae ba es C 2 7 Building and Executing a Query 2 2 2 nn C 2 8 Queries concerning the concept hierarchy C 2 9 Queries concerning the instances 2 2 2 nn nn C 2 10 Maintaining TBoxes and ABoxes 2 22 2 53 53 54 54 56 56 56 57 58 60 60 61 61 61 61 62 63 1 Introduction The RACE system is a knowledge representation system that implements a highly opti mized tableaux calculus for an expressive description logic It offers reasoning services for multiple TBoxes and for multiple ABoxes as well The system implements the description logic ALCNH p This is the basic logic ALC augmented with number restrictions role hierarchies and transitive roles RACE supports the specification of general terminological axioms A TBox may contain general concept inclusions GCIs which state the subsumption relation between two con cept terms Multiple definitions or even cyclic definitions of concepts can be handled by RACE RACE supports most of the functions specified in the Knowledge Representation System Specification KRSS for details see Patel Schneider and Swartout 93 RACE is implemented in ANSI Common Lisp and has been developed at the University of Hamburg 2 Obtaining and Running RACE T
27. Fachbereich Informatik der Universit t Hamburg Vogt K lln Str 30 D 22527 Hamburg Germany University of Hamburg Computer Science Department Mitteilung Nr 289 e Memo No 289 RACE User s Guide and Reference Manual Version 1 1 Volker Haarslev Ralf M ller Anni Yasmin Turhan Arbeitsbereich KOGS FBI HH M 289 99 Oktober 1999 RACE User s Guide and Reference Manual Version 1 1 Volker Haarslev Ralf M ller Anni Yasmin Turhan haarslev moeller turhan informatik uni hamburg de University of Hamburg Computer Science Department Vogt Kolln Str 30 22527 Hamburg Germany October 5 1999 Contents 1 Introduction 1 2 Obtaining and Running RACE 1 2 1 System Installation 2 222 a ee 1 2 2 Sample Session 2 22 24 a A Er us 1 2 3 Naming Conventions 2 222 o 5 3 RACE Knowledge Bases 5 3 1 Concept Language gt o c coac ea saa eoa a Ta arara ee 6 3 2 Concept Axioms and Terminology e 7 3 3 Role Declarations e 8 34A ABOL Assertions na wa a Gs Koes da Bod Bi A A 9 3 5 Inference Modes 2 2 20 Ae ee ee ee es 9 3 6 Retraction and Incremental Additions 0 10 4 Knowledge Base Management Functions 11 4 1 TBox Management A BoA gd ch A eh 11 POH CDOK Mo Be RA itt Pak eM ht AOS ey 11 ADELA par ahs bl Red hate A oi AR 11 Signatures iJ aa a it eh he 12 ensure tbox Signature ii ni tee A ee Go Di a 13 Feurrent tbOX o doa ee nu 3 Soa A eS Se Se a a Sa a 13 Save CDO
28. KRSS macro Checks if two concept terms subsume each other concept subsumes C1 C2 amp optional tbox current tbox Cl concept term of the subsumer Ca tbox concept term of the subsumee TBox object Returns t if C subsumes C2 and nil otherwise 29 concept subsumes p Description Syntax Arguments Values Remarks See also concept equivalent Description Syntax Arguments Values Remarks See also concept equivalent p Description Syntax Arguments Values Remarks See also function Checks if two concept terms subsume each other concept subsumes p Ci Ca tbox Cl concept term of the subsumer Ca concept term of the subsumee tbor TBox object Returns t if C subsumes C2 and nil otherwise For testing whether a concept term subsumes the other with respect to a TBoz the first argument must be a TBox If the subsumption relation is to be tested without reference to a TBox nil can be used Function concept equivalent p on page 30 macro Checks if the two concepts are equivalent in the given TBox concept equivalent C1 Ca amp optional tbor current tbox Ci C2 concept term tbox TBox object Returns t if C and C are equivalent concepts in tbor and nil otherwise For testing whether two concept terms are equivalent with respect to a TBoz the third argument must be a TBox Function atomic concept synonyms on page 39
29. Values Remarks Gets all roles from the TBox that the given role subsumes atomic role descendants RN tbox RN role name tbor TBox object List of role names This function is the transitive closure of the function atomic role descendants role ancestors KRSS macro Description Syntax Arguments Values Gets all roles from the TBox that subsume the given role in the role hierar chy role ancestors RN amp optional TBN tbox name current tbox RN role name TBN TBox name List of role names 42 atomic role ancestors function Description Syntax Arguments Values Gets all roles from the TBox that subsume the given role in the role hierar chy atomic role ancestors RN tbox RN role name tbor TBox object List of role names role children macro Description Syntax Arguments Values Remarks Gets all roles from the TBox that are directly subsumed by the given role in the role hierarchy role children RN amp optional TBN tbox name current tbox RN role name TBN TBox name List of role names This is the equivalent macro to the KRSS macro role offspring which is also supplied by the RACE system atomic role children function Description Syntax Arguments Values Gets all roles from the TBox that are directly subsumed by the given role in the role hierarchy atomic role children RN tbox RN role name
30. abox my ABox tbox function Description Gets the associated T Box for an ABox Syntax tbox abor Arguments abor ABox object Values TBox object 5 Knowledge Base Declarations Knowledge base declarations include concept axioms and role declarations for the TBox and the assertions for the ABox The TBox object and the ABox object must exist before the functions for knowledge base declarations can be used The order of axioms and assertions does not matter because forward references can be handled by RACE The macros for knowledge base declarations add the concept axioms and role declarations to the current tbox and the assertions to the current abox 5 1 Built in Concepts top top concept Description The name of most general concept of each TBox the top concept T Syntax top Remarks The concepts top and top are synonyms These concepts are elements of every TBox 18 bottom bottom concept Description The name of the incoherent concept the bottom concept L Syntax bottom Remarks The concepts bottom and bottom are synonyms These concepts are ele ments of every TBox 5 2 Concept Axioms This section documents the macros and functions for specifying concept axioms The dif ferent concept axioms were already introduced in section 3 2 Please note that the concept axioms define primitive concept define concept and define disjoint primitive concept have the semantics given in the KRSS sp
31. alice mother related alice betty has child related alice charles has child 335 Betty is mother of Doris and Eve instance betty mother related betty doris has child related betty eve has child 55 Charles is the brother of Betty and only Betty instance charles brother related charles betty has sibling 335 Closing the role has sibling for charles instance charles at most 1 has sibling 355 Doris has the sister Eve related doris eve has sister 333 Eve has the sister Doris related eve doris has sister C Web Interface C 1 Introduction The Web interface for the RACE system offers a convenient way to use a powerful taxo nomical reasoning system Based on a set of atomic concepts C and roles R it allows one to specify a set of axioms in the so called T Box It represents the terminological knowledge about the domain In the ABox one can assert that individuals are instances of specified concepts and there you can assert relations between these instances as well The reasoning services can be used via the query interface They include for example the computation of those elements of C which are direct sub and superconcepts of a concept or the computa tion of the most specific concept an individual is instance of The TBoxes and the ABoxes together with the queries can be saved separately and used when the user logs in again using the same account C 2 How to use the interface On the start page se
32. brother at most 1 has sibling Figure 3 Depiction of the ABox smith family with the explicitly given information being shown The RACE Session 333 now load the ABox CL USER 6 load race examples family abox lisp 335 Loading race examples family abox lisp T 45 some ABox queries 333 Is Doris a woman CL USER 7 individual instance doris woman T 335 Of which concepts is Eve an instance CL USER 8 individual types eve SISTER WOMAN PERSON HUMAN TOP TOP 333 get all direct types of eve CL USER 9 individual direct types eve SISTER 333 get all descendants of Alice CL USER 10 individual fillers alice has descendant DORIS EVE CHARLES BETTY 333 get all instances of the concept sister CL USER 11 concept instances sister DORIS BETTY EVE In the Appendix are different versions of this knowledge base In Appendix A on page 53 you find a version in KRSS syntax and in Appendix B on page 54 a version where the TBox and ABox are integrated 2 3 Naming Conventions Throughout this document we use the following abbreviations possibly subscripted C Concept term S List of Assertions CN Concept name GNL List of group names IN Individual name LCN List of concept names RN Role name abor ABox object ABN ABox name tbox TBox object TBN TBox name n a natural number name Name of any sort All names are Lisp symbols the concepts are symbols or lists Please note that for macros in contra
33. clause all aboxes function Description Returns all ABoxes Syntax all aboxes Values List of ABox objects all individuals o function Description Returns all individuals from the specified ABox Syntax all individuals optional abor current abox Arguments abor ABox object Values List of individual names 50 all concept assertions for individual Description Syntax Arguments Values See also all role assertions for individual in domain Description Syntax Arguments Values Remarks See also all role assertions for individual in range Description Syntax Arguments Values See also function Returns all concept assertions for an individual from the specified ABox all concept assertions for individual IN optional abox current abox IN abox individual name ABox object List of concept assertions Function all concept assertions on page 52 Junction Returns all role assertions for an individual from the specified ABox in which the individual is the role predecessor all role assertions for individual in domain IN amp optional abor current abox IN abox individual name ABox object List of role assertions Returns only the role assertions explicitly mentioned in the ABox not the inferred ones Function all role assertions on page 52 Junction Returns all role assertions for an individual from the specified ABox
34. ct subsumees of the specified concept in the TBox Syntax concept children C amp optional TBN tbox name current tbox Arguments C concept term TBN TBox name Values List of name sets Remarks Is the equivalent macro for the KRSS macro concept offspring which is also supplied in RACE atomic concept children function Description Gets the direct subsumees of the specified concept in the TBox Syntax atomic concept children C tbox Arguments C concept term tbor TBox object Values List of name sets concept parents KRSS macro Description Gets the direct subsumers of the specified concept in the TBox Syntax concept parents C amp optional TBN tbox name current tbox Arguments C concept term TBN TBox name Values List of name sets atomic concept parents function Description Gets the direct subsumers of the specified concept in the TBox Syntax atomic concept parents C tbox Arguments C concept term tbor TBox object Values List of name sets 41 role descendants KRSS macro Description Syntax Arguments Values Remarks Gets all roles from the TBox that the given role subsumes role descendants RN amp optional TBN tbox name current tbox RN role name TBN TBox name List of role names This macro is the transitive closure of the macro role children atomic role descendants function Description Syntax Arguments
35. ction At least restriction Exactly restriction I IV IA Actually the exactly restriction exactly n RN is an abbreviation for the concept term and at least n RN at most n RN There are two concepts implicitly in every TBox the concept top T denotes the top most concept in the hierarchy and the concept bottom 1 denotes the inconsistent concept which is a subconcept to all other concepts Note that T 1 can also be expressed as CuU C CMC In RACE T is denoted as top and L is denoted as bottom 3 2 Concept Axioms and Terminology RACE supports several kinds of concept axioms General concept inclusions GCIs state the subsumption relation between two concept terms DL notation C1 E Ca RACE syntax implies Ci C2 Concept equations state the equality between two concept terms DL notation Cy Ca RACE syntax equivalent C4 C2 Concept disjointness axioms states the disjointness between several concepts Disjoint concepts do not have instances in common DL notation C1 N 0 Ch L RACE syntax disjoint C Cp Actually a concept equation C1 Ca can be expressed by the two GCIs C1 E Co and Cy E Ci The disjointness of the concepts C1 Cn can also be expressed by GCIs There are also separate forms for concept axioms with just concept names on their left hand sides These concept axioms implement special kinds of GCIs and concept equations But concept names are only a special ki
36. dants 42 atomic role parents 44 attribute 8 22 bottom 19 check abox coherence 35 65 check tbox coherence 34 classify tbox 33 concept axioms 7 concept definition 8 concept equation 7 concept term 6 concept ancestors 40 concept children 41 concept descendants 39 concept disjoint p 31 concept disjoint 31 concept equivalent p 30 concept equivalent 30 concept instances 48 concept offspring 40 concept p 32 concept parents 41 concept satisfiable p 29 concept satisfiable 29 concept subsumes p 30 concept subsumes 29 concept synonyms 39 conjunction of roles 8 define concept 21 define disjoint primitive concept 21 define distinct individual 27 define primitive attribute 23 define primitive concept 20 define primitive role 23 delete ABox 17 delete T Box 14 describe abox 52 describe concept 46 describe individual 52 describe role 46 describe tbox 46 disjoint 20 disjoint concepts 7 20 21 domain restriction 9 ensure abox signature 15 ensure tbox signature 13 equivalent 20 exists restriction 6 feature 8 22 23 feature p 33 find abox 17 find tbox 14 forget 28 forget concept assertion 25 forget role assertion 27 GCI 7 19 implies 19 in abox 14 in knowledge base 16 in tbox 11 individual direct types 47 individual equal 37 individual fillers 48 individual instance p 36 individual instance 36 individual not equal 37
37. e Fig 7 you can e Register as a new user e Use the RACE Prover if you are already registered e Maintain the TBoxes and ABoxes you have built 56 Netscape RACE Prover Login O O O O OTT File Edit View Go Communicator Help 5l ut Bookmarks a Location http f kogs1 informatik uni hamburg de 8000 race Ey What s Related RACE Prover Login 06 Introduction Register as new user RACE Prover for registered users TBox Maintenance for registered users Acknowledgments Volker Haarslev and Ralf M ller University of Hamburg Computer Science Department Vogt K lln Stra e 30 e e O Figure 7 The RACE interface start page C 2 1 Register as a new user When you use RACE for the first time you must register as a new user with the register page see Fig 8 In order to do this you must fill in the fields for login name and password If you want to receive your TBoxes or your ABoxes via email the fields for name and email address must be filled in as well Building a TBox On the main page see Fig 9 TBoxes and ABoxes can be constructed and queries can be posed The TBox and the ABox are saved under the specified name when the button Eval is pressed see Fig 9 The example is is taken from Buchheit et al 93 57 Netscape RACE Prover Login http kogs1 informatik uni hamburg de GE User_xxi kkk A RK KK Figure 8 The RACE interface register page A TBox co
38. e g those queries that require the realization of the ABox 6 Reasoning Modes auto classify special variable Description Possible values are lazy eager lazy verbose eager verbose nil See also Section 3 5 on page 9 auto realize special variable Description Possible values are lazy eager lazy verbose eager verbose nil See also Section 3 5 on page 9 7 Evaluation Functions and Queries 7 1 Queries for Concept Terms 28 concept satisfiable Description Syntax Arguments Values Remarks concept satisfiable p Description Syntax Arguments Values Remarks concept subsumes Description Syntax Arguments Values macro Checks if a concept term is satisfiable concept satisfiable C optional tbox current tboxx C tbox concept term TBox object Returns t if C is satisfiable and nil otherwise For testing whether a concept term is satisfiable with respect to a TBoz the second argument must be a TBox If satisfiability is to be tested without reference to a TBox nil can be used Junction Checks if a concept term is satisfiable concept satisfiable p C tbox C tbox concept term TBox object Returns t if C is satisfiable and nil otherwise For testing whether a concept term is satisfiable with respect to a TBoz the first argument must be a TBox If satisfiability is to be tested without reference to a TBox nil can be used
39. ecification only if they are the only concept axiom defining the concept CN in the terminology This is not checked by the RACE system implies macro Description Defines a GCI between Ci and Ca Syntax implies C C Arguments Ci C2 concept term Remarks C4 states necessary conditions for Ca This kind of facility is an addendum to the KRSS specification Examples implies Grandmother and Mother Female implies and some has sibling Sister some has sibling Twin exactly 1 has sibling and Twin all has sibling Twin sister 19 equivalent Description Syntax Arguments Remarks Examples disjoint Description Syntax Arguments Examples define primitive concept Description Syntax Arguments Remarks Examples macro States the equality between two concept terms equivalent C1 C2 C1 Cy concept term This kind of concept axiom is an addendum to the KRSS specification equivalent Grandmother and Mother some has child Parent equivalent and polygon exactly 4 has angle and polygon exactly 4 has edges macro This axiom states the disjointness of a set of concepts disjoint CN CN CNi1 CN concept names disjoint Yellow Red Blue disjoint January February November December KRSS macro Defines a primitive concept define primitive concept CN C CN C concept name concept term C states the necessary conditions for CN
40. et has dog parents has pet has coach feature t Signature for an ABox signature individuals Charlie Brown Snoopy Signature for a TBox and an ABox signature atomic concepts Character Baseball Player roles has pet has dog parents has pet has coach feature t individuals Charlie Brown Snoopy Section Sample Session on page 1 and page 3 For role definitions see define primitive role on page 22 12 ensure tbox signature function Description Syntax Arguments Defines the signature for a TBox and initializes the TBox ensure tbox signature tbox amp key atomic concepts nil roles nil tbox is a TBox name or a TBox object atomic concepts is a list of all the concept names specifying C roles is a list of all role declarations thereby also specifying R current tbox special variable Description save tbox Description Syntax Arguments Values Remarks Examples The variable current tbox refers to the current TBox object It is set by the function init tbox or by the macro in tbox function If a pathname is specified a TBox is saved to a file In case a stream is specified the TBox is written to the stream the stream must already be open save tbox pathname or stream optional thor current tbox amp key syntax krss transformed nil if exists supersede if does not exist create pathname or stream is the
41. g the role hierarchy cf Buchheit et al 93 The KRSS like declaration of the role define primitive role RN and RN RN 2 can in RACE be approximated by define primitive role RN parents RN RN5 RACE does not offer constructs for domain and range restrictions for roles These restric tions for primitive roles can be simulated with GCIs see the examples in Figure 6 cf Buchheit et al 93 KRSS DL notation define primitive role RN domain C 3RN T EC define primitive role RN range C TE VRN C Figure 6 Domain and range restrictions expressed via GCls 3 4 ABox Assertions An ABox contains assertions about individuals The set of individual names Z is the signa ture of the ABox The set of individuals must be disjoint to the set of concept names and the set of role names There are two kinds of assertions Concept assertions state that an individual JN is an instance of a specified concept C Role assertions state that an individual JN is a role filler for a role RN with respect to an individual IN 9 In RACE the unique name assumption holds this means that all individual names used in an ABox refer to distinct individuals therefore two names cannot refer to the same individual In the RACE system each ABox refers to a TBox The concept assertions in the ABox are interpreted with respect to the concept axioms given in the referenced TBox The role assertions are also interpreted according to t
42. he ABox and computes the most specific concepts for each individual in the ABox realize abox amp optional abor current abox abox ABox object abox This Function needs to be executed before queries can be posed If the TBox has changed and is classified again the ABox has to be realized too 7 5 ABox Queries abox consistent p Description Syntax Arguments Values check abox coherence Description Syntax Arguments Values function Returns t iff the specified ABox object has been realized abox realized p abor abor ABox object Returns t if abox has been realized and nil otherwise function Checks if the ABox is consistent e g it does not contain a contradiction abox consistent p amp optional abor current abox abor ABox object Returns t if abox is consistent and nil otherwise Junction Checks if the ABox is consistent If there is a contradiction this function print information about the culprits check abox coherence amp optional abox current abox stream standard output abox ABox object stream Stream object Returns t if abox is consistent and nil otherwise 35 individual instance KRSS macro Description Checks if an individual is an instance of a given concept with respect to the current abox and its TBox Syntax individual instance IN C amp optional abox abox name current abox Arguments IN individual name C concept te
43. he RACE system can be obtained from the following web site http kogs www informatik uni hamburg de race html 2 1 System Installation For the Macintosh execute the self extracting archive race 1 1 sea or unstuff the file race 1 1 sit For UNIX and Windows systems decompress the archive file after downloading For UNIX use the command gzip dc race 1 1 tar gz tar xf Under Windows unzip the file race 1 1 zip This creates the files and directories of the distribution Then follow the instructions in the file readme txt 2 2 Sample Session All the files used in this example are in the directory race examples The queries are in the file family queries lisp 333 the following forms are assumed to be contained in a 333 file race examples family tbox lisp 333 initialize the TBox family in tbox family IRACE stands for Reasoner for ABoxes and Concept Expressions 333 supply the signature for this TBox signature atomic concepts person human female male woman man parent mother father grandmother aunt uncle sister brother roles has child parent has descendant has descendant transitive t has sibling has sister parent has sibling has brother parent has sibling has gender feature t domain range restrictions for roles implies top all has child person implies some has child top parent implies some has sibling top or sister brother implies top all has sibling
44. he role declarations stated in that T Box When a new ABox is built the TBox to be referenced must already exist The same TBox may be referred to by several ABoxes If no signature is used for the TBox the assertions in the ABox may use new names for roles or concepts which are not mentioned in the TBox 3 5 Inference Modes After the declaration of a TBox or an ABox RACE can be instructed to answer queries Processing the knowledge base in order to answer a query may take some time The standard inference mode of RACE ensures the following behavior Depending on the kind of query RACE tries to be as smart as possible to locally minimize computation time lazy inference mode For instance in order to answer a subsumption query wrt a TBox it is not necessary These concepts are assumed to be atomic concepts and roles are treated as roles that are neither a feature nor transitive and do not have any superroles New items are added to the TBox Note that this might lead to surprising query results e g the set of subconcepts for T contains concepts not mentioned in the TBox in any concept axiom Therefore we recommend to use a signature declaration see below to classify the TBox However once a TBox is classified answering subsumption queries for atomic concepts is just a lookup Furthermore asking whether there exists an atomic concept in a TBox that is inconsistent tbox coherent p does not require the TBox to be classified either
45. hecks wether the two concepts from C are equivalent RACE syntax equivalentp CN1 CN2 61 parent has pesy satz lien predator mupersoncep e dandelion plant carnivore animall aninal gt plant gubconcepte animal animal plant stganiem Miden rabbit aquivralentpL has prey animal omnivore animali carnivace animal aynonymalcacrnivors animali animal 411 ata animal rabbit dandelian herbivore animal eats retrievs lanimall animal all eata plant inatancep rabbit amivccs imal plank predators animal 5 mecicabbitl all satz organiam predator animal 4 lall has prey animal Figure 10 Some example queries Synonyms finds all concept names in C that are equivalent to CN RACE syntax synonyms CN C 2 9 Queries concerning the instances Instancep checks if the specified individual is an instance of the specified concept C RACE syntax instancep i C Retrieve finds all individuals in the current ABox that are instances of a concept C RACE syntax retrieve C Most specific concepts finds the most specific concept names in C of which the specified individual is an instance of RACE syntax msc i 62 Netscape Bae btadalprinee lor regrese Figure 11 The RACE maintenance page The queries in the pane are executed after the Eval button is clicked The response of the RACE system is displayed in the lower part of the main dialog as y
46. in which the individual is a role successor all role assertions for individual in range IN amp optional abor current abox IN abox individual name ABox object List of assertions Function all role assertions on page 52 ol all concept assertions Description Syntax Arguments Values all role assertions Description Syntax Arguments Values See also describe abox Description Syntax Arguments Values describe individual Description Syntax Arguments Values Junction Returns all concept assertions from the specified ABox all concept assertions amp optional abor current abox abor ABox object List of assertions Junction Returns all role assertions from the specified ABox all role assertions amp optional abor current abox IN abox individual name ABox object List of assertions Function all concept assertions for individual on page 31 Junction Generates a description for the specified ABox describe abox amp optional abox current abox stream standard output ABox object stream open stream object abox abox The description is written to stream Junction Generates a description for the individual from the specified ABox describe individual N amp optional abox current abox stream standard output IN abox individual name ABox object stream open stream objec
47. ividuals from an ABox that are instances of the specified concept Syntax concept instances C amp optional ABN abox name current abox Arguments C concept term ABN ABox name Values List of individual names retrieve concept instances function Description Gets all individuals from an ABox that are instances of the specified concept Syntax retrieve concept instances C abox Arguments C concept term abor ABox object Values List of individual names individual fillers KRSS macro Description Gets all individuals that are fillers of a role for a specified individual Syntax individual fillers IN RN optional ABN abox name current abox Arguments IN individual name of the predecessor RN role name ABN ABox name Values List of individual names Examples individuals fillers Charlie Brown has pet 48 retrieve individual fillers Description Syntax Arguments Values Examples retrieve related individuals Description Syntax Arguments Values Examples See also retrieve individual relations Description Syntax Arguments Values Examples See also Junction Gets all individuals that are fillers of a role for a specified individual retrieve individual fillers IN RN abos IN individual name of the predecessor RN role name abox ABox object List of individual names individuals fillers Charlie Brown has pet
48. jointness is to be tested without reference to a TBox nil can be used alc concept coherent function Description Tests the satisfiability of a Km K4 m or S4 m formula encoded as an ALC concept Syntax alc concept coherent C amp key logic k Arguments C concept term logic specifies the logic to be used K modal Kin K4 modal K4 all roles are transitive S4 modal S4 m all roles are transitive and reflexive If no logic is specified the logic K is chosen Remarks This function can only be used for ALC concept terms so number restrictions are not allowed 31 7 2 Role role subs Description Syntax Arguments Values role subs Description Syntax Arguments Values concept p Description Syntax Arguments Values role p Description Syntax Arguments Values Queries umes KRSS macro Checks if two roles are subsuming each other role subsumes RN RN optional TBN tbox name current tbox RN role name of the subsuming role RN role name of the subsumed role TBN TBox name Returns t if RN is a parent role of RN umes p function Checks if two roles are subsuming each other role subsumes p RN RN tbox RN role name of the subsuming role RN role name of the subsumed role tbor TBox object Returns t if RN is a parent role of RNa function Checks if CN is a concept name for a concept in the specified TBox concept p
49. ld person define concept mother and woman parent define concept father and man parent define concept grandmother and mother some has child some has child person 53 define concept aunt and woman some has sibling parent define concept uncle and man some has sibling parent define concept brother and man some has sibling person define concept sister and woman some has sibling person A 2 KRSS Sample ABox 333 the following forms are assumed to be contained in a 333 file race examples family abox krss lisp 333 initialize the ABox smith family and use the TBox family in abox smith family family 335 Alice is the mother of Betty and Charles instance alice mother related alice betty has child related alice charles has child 335 Betty is mother of Doris and Eve instance betty mother related betty doris has child related betty eve has child Charles is the brother of Betty and only Betty instance charles brother related charles betty has sibling 335 closing the role has sibling for charles instance charles at most 1 has sibling 355 Doris has the sister Eve related doris eve has sister 333 Eve has the sister Doris related eve doris has sister B Integrated Sample Knowledge Base This section shows an integrated version of the family knowledge base 333 the following forms are assumed to be contained in a 333 file race examples family kb lisp
50. nd of concept terms so these forms are just syntactic sugar They are added to the RACE system for historical reasons and for compatibility with KRSS These concept axioms are Primitive concept axioms state the subsumption relation between a concept name and a concept term DL notation CN E C RACE syntax define primitive concept CN C For KRSS compatibility reasons RACE also supports the synonym concepts top and bottom Concept definitions state the equality between a concept name and a concept term DL notation CN C RACE syntax define concept CN C Concept axioms may be cyclic in RACE There may also be forward references to concepts which will be introduced with define concept or define primitive concept in sub sequent axioms The terminology of a RACE TBox may also contain several axioms for a single concept So if a second axiom about the same concept is given it is added and does not overwrite the first axiom 3 3 Role Declarations In contrast to concept axioms role declarations are unique in RACE There exists just one declaration per role name in a knowledge base If a second declaration for a role is given an error is signalled If no signature is specified undeclared roles are assumed to be neither a feature nor a transitive role and they do not have any superroles The set of all roles R includes the set of features F and the set of transitive roles RT The sets F and R are disjoint All roles
51. nt abox Arguments IN IN individual name abor abox object Remarks Because the unique name assumption holds in RACE this macro always returns nil for individuals with different names This macro is just supplied to be compatible with the KRSS individual not equal KRSS macro Description Checks if two individual names do not refer to the same individual Syntax individual not equal IN INa amp optional abox current abox Arguments IN IN individual name Remarks abox abox object Because the unique name assumption holds in RACE this macro always returns t for individuals with different names This macro is just supplied to be compatible with the KRSS 37 individual p function Description Syntax Arguments Values Checks if IN is a name of an individual individual p IN amp optional abor current abox IN individual name abox ABox object Returns t if JN is a name of an individual and nil otherwise 8 Retrieval If the retrieval refers to concept names RACE always returns a set of names for each concept name A so called name set contains all synonyms of an atomic concept in the TBox 8 1 TBox Retrieval taxonomy Description Syntax Arguments Values Examples See also function Returns the whole taxonomy for the specified TBox taxonomy optional thor current tbox tbor TBox object A list of triples each of it consisting of a name set
52. ntains role declarations role axioms and concept axioms The set of concept terms used in the concept axioms of a TBox is always based on the set of concept names the atomic concepts In the RACE system the set of concept names C is extracted automatically from the concept axioms mentioned in the TBox The set of roles R consists of three disjoint sets The set of primitive roles the set of transitive roles and the set of features The set of roles R is also extracted automatically from the TBox by the RACE system The transitive roles and the features are given by role declarations The undeclared roles are assumed to be primitive roles Hierarchical relations between roles are stated by role axioms s b In the following the syntax for concept axioms is explained C 2 2 Concept axioms RACE supports two kinds of concept axioms We first give the usual German style DL notation and afterwards the ASCII counterpart of the operators explained In the following C with index denotes a concept term General concept inclusions GCIs state the subsumption relation between two concept terms 58 Helicipa AACE Prower al irka rmtik una haubeurg de BUN For P ROR SENSE 73 F some tennhien COURSE john cel56 instanc p john PROF STUDERT amp some degree BS teacher PROF N ingtanesp john STUDENT john PROH gt some degree Ms lat noat 1 degres as degree Me gt csl56 COURSE some degree BS
53. obably be located separately from the associated TBoxes in order to save processing time During the development phase of a TBox it might be advantageous to call inference services directly For instance during the development phase of a TBox it might be useful to check which atomic concepts in the TBox are inconsistent by calling check tbox coherence This service is usually much faster than calling classify tbox However if an application prob lem can be solved for example by checking whether a certian ABox is consistent or not see the function abox consistent p it is not necessary to call either check tbox coherence or classify tbox For all queries RACE ensures that the knowledge bases are in the ap propriate states This behavior usually guarantees minimum runtimes for answering queries 3 6 Retraction and Incremental Additions RACE offers constructs for retracting ABox assertions see forget forget concept assertion and forget role assertion If a query has been an swered and some assertions are retracted then RACE might be forced to realize the ABox again i e after retractions some queries might take some time to answer RACE also supports incremental additions to ABoxes i e assertions can be added even after queries have been answered However the internal data structures used for anwering queries are recomputed from scratch This might take some time If an ABox is used for hypothesis generation e g for testing whether
54. on Values thor Remarks RACE imposes no constraints on the sequence of concept axiom declara tions with add concept axiom i e forward references to atomic concepts for which other concept axioms are added later are supported in RACE add disjointness axiom function Description This function adds a disjointness concept axiom to a TBox Syntax add disjointness axiom thor CN GN Arguments thor TBox object CN concept name GN _ group name Values thor 5 3 Role Declarations 22 define primitive role KRSS macro with changes Description Syntax Arguments Remarks Examples See also Defines a role define primitive role RN amp key transitive nil feature nil parents nil RN role name transitive if bound to t declares that the new role is transitive feature if bound to t declares that the new role is a feature if feature is bound to t parents provides a list of superroles for the new role The role RN has no superroles if parents is bound to nil If only a single superrole is specified the keyword parent may alternatively be used see the examples This function combines several KRSS functions for defining properties of a role For example the conjunction of roles can be expressed as shown in the first example below A role that is declared to be a feature cannot be transitive A role with a feature as a parent has to be a feature itself A role with transitive subroles may not
55. or sister brother implies top all has sister some has gender female implies top all has brother some has gender male 333 the concepts implies person and human some has gender or female male disjoint female male implies woman and person some has gender female implies man and person some has gender male equivalent parent and person some has child person equivalent mother and woman parent equivalent father and man parent equivalent grandmother and mother some has child some has child person equivalent aunt and woman some has sibling parent equivalent uncle and man some has sibling parent equivalent brother and man some has sibling person equivalent sister and woman some has sibling person i as gender has brother has sibling has sister as descendant HH has child Figure 1 Role hierarchy for the family TBox r denotes the universal role which may not be used in knowledge bases denotes features x denotes transitive roles parent mother grandmother sister Figure 2 Concept hierarchy for the family TBox The RACE Session 333 load the TBox CL USER 1 load race examples family tbox lisp 335 Loading race examples family tbox lisp T CERO some TBox queries 55 are all uncles brothers CL USER 2 concept subsumes brother uncle T 333 get all super concepts of the concep
56. ou can see in Fig 9 A negative answer such as It cannot be proven that J is an instance of C for queries like instancep i C may seem surprising for someone who expected No RACE avoids No because this might suggest that in this case is an instance of A Considering the TBox D AU B with the ABox i D it cannot be inferred that the individual is an instance of A or not C 2 10 Maintaining TBoxes and ABoxes From the RACE start page you can go to the maintenance page see Fig 11 There you find all the names of your TBoxes and ABoxes with their associated Queries listed In this dialog you can delete TBoxes or ABoxes You can also send a TBox or an ABox to yourself via email if you have filled in your email address for this account 63 References Buchheit et al 93 M Buchheit F M Donini amp A Schaerf Decidable Reasoning in Ter minological Knowledge Representation Systems in Journal of Artificial Intelligence Research 1 pp 109 138 1993 Haarslev and M ller 99 V Haarslev and R M ller Expressive ABox Reasoning with Number Restrictions Role Hierarchies and Transitively Closed Roles Technical Re port FBI HH M 288 99 University of Hamburg 1999 Horrocks et al 99a I Horrocks U Sattler S Tobies Practical Reasoning for Descrip tion Logics with Functional Restrictions Inverse and Transitive Roles and Role Hier archies Proceedings of the 1999 Work
57. pathname of a file or an output stream tbor TBox object syntax indicates the syntax of the TBox It might as well be names of other DL systems transformed if bound to t the TBox is saved in the format after preprocess ing by RACE if exists specifies the action taken if a file with the specified name already exists All keywords for the Lisp function with open file are sup ported The default is supersede if does not exist specifies the action taken if a file with the specified name does not yet exist All keywords for the Lisp function with open file are supported The default is create TBox object A file may contain several TBoxes The usual way to load a TBox file is to use the Lisp function load save tbox project TBoxes tbox one lisp save tbox project TBoxes final tbox lisp find tbox tbox one if exists error 13 find tbox Description Returns a TBox object with the given name among all TBoxes Syntax find tbox TBN optional errorp t Arguments TBN is the name of the TBox to be found errorp if bound to t an error is signalled if the TBox is not found Values TBox object Remarks This function can also be used to get rid of TBoxes or rename TBoxes as shown in the examples Examples find tbox my TBox Getting rid of a TBox setf find tbox tbox1 nil Renaming a TBox setf find tbox tbox2 tbox1 tbox name function Description Finds the name of the given TBox object
58. quent queries the index structures for the ABox will be recomputed i e some queries might take some time e g those queries that require the realization of the ABox Examples forget concept assertion find abox peanuts characters Lucy Person forget concept assertion find abox peanuts characters Snoopy and Dog Cartoon Character 25 related Description KRSS macro Builds a role assertion asserts that two individuals are related via a role or feature Syntax related IN INa RN Arguments IN individual name of the predecessor IN individual name of the filler RN arole name or a feature name Examples related Charlie Brown Snoopy has pet related Lucy Linus has brother add role assertion function Description Adds a role assertion to an ABox Syntax add role assertion abor IN IN2 RN Arguments abor ABox object IN individual name of the predecessor IN individual name of the filler RN role name Values abox Examples add role assertion find abox peanuts characters Charlie Brown Snoopy has pet add role assertion find abox peanuts characters Lucy Linus has brother 26 forget role assertion function Description Syntax Arguments Values Remarks Examples Retracts a role assertion from an ABox forget role assertion abox IN IN2 RN abor ABox object IN individual name of the predecessor IN individual name of
59. rm abox ABox object Values Returns t if IN is an instance of C in abox and nil otherwise individual instance p function Description Checks if an individual is an instance of a given concept with respect to an ABox and its TBox Syntax individual instance p IN C abor Arguments IN individual name C concept term abox ABox object Values Returns t if IN is an instance of C in abox and nil otherwise individuals related macro Description Checks if two individuals are directly related via the specified role Syntax individuals related IN IN RN amp optional abor current abox Arguments IN individual name of the predecessor IN individual name of the role filler RN role name abor ABox object Values Returns t if IN is related to IN via RN in abox and nil otherwise 36 individuals related p function Description Checks if two individuals are directly related via the specified role Syntax individuals related p IN IN RN abor Arguments IN individual name of the predecessor IN individual name of the role filler RN role name abor ABox object Values Returns t if JN is related to IN via RN in abox and nil otherwise See also Function retrieve individual relations on page 49 Function retrieve related individuals on page 49 individual equal KRSS macro Description Checks if two individual names refer to the same individual Syntax individual equal IN IN2 optional abor curre
60. shop Methods for Modalities M4M 1 Ams terdam 1999 Horrocks et al 99b I Horrocks U Sattler S Tobies A Description Logic with Transitive and Converse Roles Role Hierarchies and Qualifying Number Restrictions Technical Report LTCS 99 08 RWTH Aachen 1999 Patel Schneider and Swartout 93 P F Patel Schneider B Swartout Description Logic Knowledge Representation System Specification from the KRSS Group of the ARPA Knowledge Sharing Effort November 1993 The paper is available as http www db research bell labs com user pfps papers krss spec ps 64 Index xauto classify 28 auto realize 28 bottom 19 current abox 16 current tbox 13 topx 18 abox consistent p 35 abox name 18 abox realized p 35 add concept assertion 25 add concept axiom 22 add disjointness axiom 22 add role assertion 26 add role axiom 24 alc concept coherent 31 all aboxes 50 all atomic concepts 45 all concept assertions 52 all concept assertions for individual 51 all features 45 all individuals 50 all role assertions 52 all role assertions for individual in domain 51 all role assertions for individual in range 51 all roles 45 all tboxes 44 all transitive roles 45 assertion 9 atomic concept ancestors 40 atomic concept children 41 atomic concept descendants 40 atomic concept parents 41 atomic concept synonyms 39 atomic role ancestors 43 atomic role children 43 atomic role descen
61. st to functions the arguments should not be quoted The API is designed to the following conventions For most of the services offered by RACE macro interfaces and function interfaces are provided For macro forms the TBox or ABox arguments are optional If no TBox or ABox is specified the xcurrent tbox or current abox is taken respectively However for the functional counterpart of a macro the TBox or ABox argument is not optional For functions who do not have macro counter parts the TBox or ABox argument may or may not be optional Furthermore if an argument tbox or abox is specified in this documentation a name a symbol can be used as well 3 RACE Knowledge Bases In description logic systems a knowledge base is consisting of a TBox and an ABox The conceptual knowledge is represented in the TBox and the knowledge about the instances of a domain is represented in the ABox For a more detailed description of the concept language supported by RACE see Haarslev and M ller 99 3 1 Concept Language The content of RACE TBoxes includes the conceptual modeling of concepts and roles as well The modelling is based on the signature which consists of two disjoint sets the set of concept names C also called the atomic concepts and the set R containing the role names Starting form the set C complex concept terms can be build using several operators An overview over all concept building operators is given in Figure 4 C CN
62. stream open stream object Values tbox or abox The description is written to stream 8 2 ABox Retrieval 46 individual direct types Description Syntax Arguments Values most specific instantiators Description Syntax Arguments Values individual types Description Syntax Arguments Values Remarks instantiators Description Syntax Arguments Values Remarks KRSS macro Gets the most specific atomic concepts of which an individual is an instance individual direct types IN amp optional ABN abox name current abox IN ABN ABox name individual name List of name sets Junction Gets the most specific atomic concepts of which an individual is an instance most specific instantiators IN abox IN abox individual name ABox object List of name sets KRSS macro Gets all atomic concepts of which the individual is an instance individual types IN amp optional ABN abox name current abox IN individual name ABN ABox name List of name sets This is the transitive closure of the KRSS macro individual direct types function Gets all atomic concepts of which the individual is an instance instantiators IN abox IN abox individual name ABox object List of name sets This is the transitive closure of the function most specific instantiators 47 concept instances KRSS macro Description Gets all ind
63. t IN The description is written to stream 52 A KRSS Sample Knowledge Base The following knowledge base is specified in KRSS syntax It is a version of the knowledge base used in the Sample Session on page 1 A 1 KRSS Sample TBox 333 the following forms are assumed to be contained in a 333 file race examples family tbox krss lisp 333 initialize the TBox family in tbox family init t 33 the roles define primitive role has child parents has descendant define primitive role has descendant transitive t define primitive role has sibling define primitive role has sister parents has sibling define primitive role has brother parents has sibling define primitive attribute has gender 335 domain range restrictions for roles implies top all has child person implies some has child top parent implies some has sibling top or sister brother implies top all has sibling or sister brother implies top all has sister some has gender female implies top all has brother some has gender male 333 the concepts define primitive concept person and human some has gender or female male define disjoint primitive concept female gender top define disjoint primitive concept male gender top define primitive concept woman and person some has gender female define primitive concept man and person some has gender male define concept parent and person some has chi
64. t mother 333 This kind of query yields a list of so called name sets KR which are lists of equivalent atomic concepts CL USER 3 concept ancestors mother PARENT WOMAN PERSON TOP TOP HUMAN 333 get all sub concepts of the concept man CL USER 4 concept descendants man UNCLE BOTTOM BOTTOM BROTHER FATHER 333 get all transitive roles in the TBox family CL USER 5 all transitive roles HAS DESCENDANT 333 the following forms are assumed to be contained in a 333 file race examples family abox lisp 333 initialize the ABox smith family and use the TBox family in abox smith family family 333 supply the signature for this ABox signature individuals alice betty charles doris eve 335 Alice is the mother of Betty and Charles instance alice mother related alice betty has child related alice charles has child 335 Betty is mother of Doris and Eve instance betty mother related betty doris has child related betty eve has child Charles is the brother of Betty and only Betty instance charles brother related charles betty has sibling closing the role has sibling for Charles instance charles at most 1 has sibling 355 Doris has the sister Eve related doris eve has sister 333 Eve has the sister Doris related eve doris has sister doris has child betty mother has has sister child alice mother has sibling EVE charles and
65. the assertion 7 C can be added without causing an inconsistency we recommend using the instance checking inference service If individual instance i not C returns t i C cannot be added to the ABox Now let us assume we can add 7 C and afterwards want to test whether 7 D can be added without causing an inconsistency In this case it might be faster not to add i C directly but to check whether individual instance i and C not D returns t The reason is that in this case the index structures for the ABox are not recomputed 10 4 Knowledge Base Management Functions This section documents the functions for managing TBoxes and ABoxes and for specifying queries 4 1 TBox in tbox Description Syntax Arguments Remarks Examples See also init tbox Description Syntax Arguments Values Remarks Management macro The TBox with the specified name is taken or a new TBox with that name is generated and bound to the variable current tbox in tbox TBN amp key init nil TBN is the name of the TBox init boolean indicating if the TBox should be initialized Usually this macro is used at top of a file containing a TBox This macro can also be used to create new TBoxes The specified TBox is the current tbox until in tbox is called again or the variable current tbox is manipulated directly in tbox peanuts implies Piano Player Character Macro signature on page
66. the atomic concept CN and its synonyms list of concept parents name sets each entry being a list of a concept parent of CN and its synonyms list of concept children name sets each entry being a list of a concept child of CN and its synonyms taxonomy my TBox may yield Gtop quadrangle tetragon quadrangle tetragon top rectangle diamond rectangle quadrangle tetragon bottomx diamond quadrangle tetragon bottom bottom rectangle diamond Function atomic concept parents function atomic concept children on page 41 38 concept synonyms Description Syntax Arguments Values Remarks See also atomic concept synonyms Description Syntax Arguments Values Remarks See also concept descendants Description Syntax Arguments Values Remarks macro Returns equivalent concepts for the specified concept in the given TBox concept synonyms CN optional tbox tbox name current tbox CN tbox concept name TBox object List of concept names The name CN is not included in the result Function concept equivalent p on page 30 function Returns equivalent concepts for the specified concept in the given TBox atomic concept synonyms CN tbox CN tbox concept name TBox object List of concept names The name CN is not included in the result Function concept equivalent p on page 30
67. the specified TBox all roles amp optional tbor current tbox tbox TBox object List of roles names all roles find tbox my tbox Junction Returns all features from the specified TBox all features amp optional tbox current tbox thor TBox List of feature names Junction Returns all transitive roles from the specified TBox all transitive roles optional tbox current tbox tbox TBox object List of transitive role names 45 describe tbox function Description Generates a description for the specified TBox Syntax describe tbox optional tbox current tbox stream standard output Arguments thor TBox object or TBox name stream open stream object Values tbox The description is written to stream describe concept function Description Generates a description for the specified concept used in the specified TBox or in the ABox and its TBox Syntax describe concept CN optional tbox or abor current tbox stream standard output Arguments tbox or abox TBox object or ABox object CN concept name stream open stream object Values tbox or abox The description is written to stream describe role function Description Generates a description for the specified role used in the specified TBox or ABox Syntax describe role RN optional tbox or abox current tbox stream standard output Arguments tbox or abox TBox object or ABox object RN role name or feature name
68. ved in the format it has after preprocessing by RACE if exists specifies the action taken if a file with the specified name already exists All keywords for the Lisp function with open file are sup ported The default is supersede if does not exist specifies the action taken if a file with the specified name does not yet exist All keywords for the Lisp function with open file are supported The default is create Values ABox object Remarks A file may contain several ABoxes The usual way to load an ABox file is to use the Lisp function load Examples save abox project ABoxes abox one lisp save abox project ABoxes final abox lisp find abox abox one if exists error find abox function Description Finds an ABox object with a given name among all ABoxes Syntax find abox ABN optional errorp t Arguments ABN is the name of the ABox to be found errorp if bound to t an error is signalled if the ABox is not found Values ABox object Remarks This function can also be used to delete ABoxes or rename ABoxes as shown in the examples Examples find tbox my ABox Get rid of an ABox i e make the ABox garbage collectible setf find abox abox1 nil 17 Renaming an ABox setf find abox abox2 abox1 abox name function Description Finds the name of the given ABox object Syntax abox name abos Arguments abor ABox object Values ABox name Examples abox name find

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