07:12:21 RRSAgent has joined #rif 07:12:21 logging to http://www.w3.org/2007/06/02-rif-irc 07:12:34 zakim, this is rif 07:12:34 ok, ChrisW; that matches SW_RIF(F2F)2:30AM 07:12:52 Meetin: RIF F2F meeting 2 June 2007 07:12:57 Meeting: RIF F2F meeting 2 June 2007 07:13:14 Chair: Christian de Sainte-Marie 07:13:23 Chair: Chris Welty 07:13:48 DaveReynolds_ has joined #rif 07:14:53 ChrisWelty has joined #rif 07:15:47 sandro has joined #rif 07:15:51 http://www.w3.org/2005/rules/wg/charter.html#xml-syntax 07:16:04 "The primary normative syntax of the language must be an XML syntax. Users are expected to work with tools or rule languages which are transformed to and from this format." 07:16:14 Agenda: http://www.w3.org/2005/rules/wg/wiki/F2F6 07:17:10 AllenGinsberg has joined #rif 07:17:55 can someone dial-in to zakim? 07:18:20 Mike, they try it now. 07:18:29 thanx 07:18:52 zakim, this is rif 07:18:52 sandro, this was already SW_RIF(F2F)2:30AM 07:18:53 ok, sandro; that matches SW_RIF(F2F)2:30AM 07:19:06 + +43.512.507.aaaa 07:19:20 Zakim, aaaa is F2F-Meeting 07:19:20 +F2F-Meeting; got it 07:19:31 AllenG has joined #rif 07:21:56 ChrisW has joined #rif 07:22:56 zakim, list agenda 07:22:56 I see 1 item remaining on the agenda: 07:22:57 7. AOB [from ChrisW] 07:23:02 zakim, clear agenda 07:23:02 agenda cleared 07:23:12 agenda+ Overivew of meeting agenda 07:23:17 zakim, next item 07:23:17 agendum 1. "Overivew of meeting agenda" taken up [from ChrisW] 07:24:44 3.2. Phase 2 Scope: http://www.w3.org/2005/rules/wg/charter.html#actions 07:25:26 agenda+ Abstract Syntax 07:26:03 testing 1 2 3 07:26:10 Adrian G 07:26:46 johnhall has joined #rif 07:27:03 zakim, who is on the phone? 07:27:03 On the phone I see Mike_Dean, F2F-Meeting 07:28:23 http://www.w3.org/2005/rules/wg/charter.html#horn 07:28:32 "The Phase 1 rule semantics will be essentially Horn Logic, a well-studied sublanguage of First-Order Logic which is the basis of Logic Programming." 07:28:33 zakim, f2f-meeting contains Hassan, Igor, Jos, Giorgos, DaveR, Gary, Axel, MichealS, Markus, Paula, Francois, Allen, JohnH, Harold, Sandro, Chris, Christian, AdrianG, MichealK 07:28:33 +Hassan, Igor, Jos, Giorgos, DaveR, Gary, Axel, MichealS, Markus, Paula, Francois, Allen, JohnH, Harold, Sandro, Chris, Christian, AdrianG, MichealK; got it 07:28:36 DaveReynolds has joined #rif 07:29:25 zakim, next item 07:29:25 agendum 2. "Abstract Syntax" taken up [from ChrisW] 07:33:31 zakim, PaulV is in f2f-meeting 07:33:32 +PaulV; got it 07:35:37 http://www.w3.org/2005/rules/wg/charter.html#xml-syntax 07:35:55 "... In order to allow interoperability with RDF and object-oriented systems, the syntax must support named arguments (also called "role" or "slot" names), allowing n-ary facts, rules, and queries to be provided through property/value interfaces ...." 07:40:23 agiurca has joined #rif 07:42:01 sandro: omitted sort == universal sort? jos: yes 07:42:09 EBNF syntax for sorts: "value"^^sortname 07:42:36 http://www.w3.org/2005/rules/wg/wiki/Core/Positive_Conditions#sec-multisorted-logic 07:43:17 PaulVincent has joined #rif 07:44:06 Const: "123"^^xsd:long and Vars: ?v^^xsd:dateTime 07:44:57 GaryHallmark has joined #rif 07:45:21 Francois: what is in logic is called "sort" is called in programming "types" 07:45:57 Francois: and in this group we're using it with the meaning of "syntactic category" 07:46:06 at some places still arrow_sort appears... search and replace should solve that. 07:46:19 Harold: surely for vars one would want to separate type declaration from usage and not repeat the annotation at each usage 07:47:37 Dave, right, the place in the is the distinguished occurrence, where sorting should be done once. 07:47:58 CGI333-allen has joined #rif 07:48:34 Francois, we had 'type', then the WG wanted to use 'sort': compatible with that notion in 'order-sorted logic'. 07:49:42 Hassan, we have that: signature NAME s1 * ... * sn ? s , r1 * ... * rk ? r , ... 07:50:11 Hassan, we have that: signature NAME s1 * ... * sn ->? s , r1 * ... * rk -> r , ... 07:50:27 Hassan, we have that: signature NAME s1 * ... * sn -> s , r1 * ... * rk -> r , ... 07:51:05 CGI333-allen = AllenG = AllenGinsberg 07:51:09 zakim, who is here? 07:51:09 On the phone I see Mike_Dean, F2F-Meeting 07:51:10 F2F-Meeting has Hassan, Igor, Jos, Giorgos, DaveR, Gary, Axel, MichealS, Markus, Paula, Francois, Allen, JohnH, Harold, Sandro, Chris, Christian, AdrianG, MichealK, PaulV 07:51:14 On IRC I see CGI333-allen, GaryHallmark, PaulVincent, agiurca, DaveReynolds, johnhall, ChrisW, AllenG, AllenGinsberg, sandro, RRSAgent, Harold, Hassan, GiorgosStoilos, msintek, 07:51:16 ... MarkusK, josb, PaulaP, AxelPolleres, mdean, Zakim, rifbot 07:53:12 Who here has actually carefully read the text http://www.w3.org/2005/rules/wg/wiki/Core/Positive_Conditions#sec-multisorted-logic ? 07:54:10 Francois, we have this: Forall x^^HumanBeing y^^TelephoneNumber (has(x y) :- wantToBeConnected(x y)) 07:54:39 sandro: I reviewed the original version; don't know if it changed much since then 07:55:41 IgorMozetic has joined #rif 07:56:12 Francois, we have this: Forall x^^HumanBeing y^^TelephoneNumber (has(x y) :- wantToBeConnected(x)) 07:59:41 Franc has joined #rif 08:00:04 Adrian, if your office phone is 1234, we have this: has(Adrian^^HumanBeing 1234^^TelephoneNumber) 08:00:08 Franc = Francois 08:00:53 I completely agree 08:02:06 Does it make sense to say 7^^primeNumber ? 08:05:03 I guess we may have Sort (abstract) subclassed by Type, ASort and BSort . Then ?x^^Predicate is possible, where Predicate is an instance of BSort. Also is possible to have ?x^^Computer where Computer is associated with an ASort (a catresian product of Type instances) Scribe: Franc 08:05:20 Francois: we should nt confuse (1) syntactical categories, (2) sorts in the sense of programming types, and (3) casting i.e. conversion between values from different sorts (in the senser of programming language types). 08:05:51 Alex: I suggest a generalization of this. 08:06:00 s/Alex/Axel 08:08:01 Axel: we could consider Boolean signatures as special arrow signatures with result type Boolean. 08:08:45 axel: and primitive sorts are arrow signatures of 0-arity 08:09:11 Dave: we use the diagramas as abstract syntax. does not say what is declared. 08:09:17 +1 Gary 08:11:12 Sandro, so far we did not have things like 7^^primeNumber on the 'top-level' of statements but only within Atoms/Uniterms like age(Mary^^HumanBeing 7^^primeNumber). 08:11:57 However, in the recent slotted/frame extension, 7^^primeNumber would be ok *as* a statement. 08:12:11 Hassan: suggest on the bord to distinguish between: signatures as sets of symbols. 08:13:42 With a signature, one can ssociate sorts (one sort of each symbol). Sorts understood as arities. 08:15:15 Christian: Why is this different from signature in our document? 08:15:20 Hassan: it is not. 08:16:08 Axel: Can the notion of eg Boolean sorts and signature sort be unified in one notion? 08:17:08 Michael: Is the issue to get rid of the name 'sort'? 08:18:55 Axel: draws on the borad: Terms consist of symbols that are var or cons. We laso have uniterm. For each symbol we would have a signature. 08:19:26 Michael, Francois and Mike, could we solve Francois' concern about (1) syntactical categories, (2) sorts by expressing (1) as name spaces and (2) local names, e.g. for (1) Ind vs. Data and for (2) HumanBeing vs. dateTime, as in.../rif/Ind#HumanBeing vs. .../Data/xsd#dateTime. 08:21:33 Michael: What is the issue? 08:21:53 hristian: Sorts appear everywhere in the doc but nowhere in the abstract syntax. 08:22:05 christian: the issue is how to add sorts to the ASN 08:23:57 Dave: This diagram is a syntax no data model. 08:25:45 Adrian: terms are associated with signatures. 08:26:02 Axel: we have several signatures. Signature 0 is just the sorts. 08:26:46 Axel: collapse different versions of signatures unless distinctions are essential 08:30:40 In document: Const ::= CONSTNAME | '"'CONSTNAME'"''^^'SORTNAME 08:30:40 Var ::= '?'VARNAME | '?'VARNAME'^^'SORTNAME 08:30:54 from http://www.w3.org/2005/rules/wg/wiki/Core/Positive_Conditions 08:31:00 Chris: confusion is arising from mixing up syntax and semantics/data model. Let us use EBNFs for clarity and only derive normative UML in the end. 08:33:29 Chris: writes down a BNF grammar and claims it expresses the same as the diagramme. 08:36:39 csma: the sorts associated with var are ONLY in the declaration, not in the variable usage. 08:37:04 SORTNAME is a "REFERENCE" is not the sort itself. The name is a selfrefenece to the sort. 08:39:25 Harold: in some formalisms, complex terms can be used as operators, hence they need signatures too. 08:40:10 Harold: HiLOG is an example for this. 08:40:24 csma: ok, but this needs to be restricted for RIF Core 08:41:36 RRSAgent, pointer? 08:41:36 See http://www.w3.org/2007/06/02-rif-irc#T08-41-36 08:43:03 IF RIF will have a vocabulary (for example RDFS) part then Const Var etc will "refer" the schema parts by ising references (in XML they can be URI) 09:03:26 PaulVincent has joined #rif 09:03:31 ScribeNick: AllenG 09:03:38 GiorgosStoilos has joined #rif 09:03:46 msinte1 has joined #rif 09:04:12 csma: pick up from last session 09:05:20 Adrian, right we have the option of this kind of 'webizing'. 09:05:34 csma: only thing that needs a sort in syntax is var 09:05:52 csma: ... asssuming that there is a declaration section 09:06:15 s/chris/csma 09:06:22 Chris: maybe the only thing that needs sorts are variables in the condition diagram, assuming sorts for consts are delcared some place. 09:06:44 Jos: A symbol may have different sorts -- so it may be distinguish the different sorts in each use. 09:06:48 jos: symbol may have different sorts 09:07:20 MichaelK: I think you mean signatures 09:08:23 chris: let's get on the same page NOW! 09:08:52 chris: we are talking about the syntax for conditions (a la diagram) 09:10:00 Harold: var's can have different sorts in same condition 09:10:18 harold: but they must be compatible 09:10:42 chris: might be getting confused about what a sort is: look in doc 09:11:27 Michael: every constant has a sort. 09:12:08 michael: sorts are part of the language; you declare a const as a sort 09:12:26 chris: what sorts are there, other than primitives 09:12:41 michael: sorts can be user definable 09:12:53 chris: now I am confused 09:13:05 adrian: sort is a classifer for a const or var 09:13:23 csma: like a type in a prog lang? 09:13:28 adrian: could be 09:13:43 axel: use sorts to distinguish pred and fcn? 09:13:54 chris: not according to what I heard 09:14:20 axel: rules can assign sorts to things 09:15:07 michael: you can write rules that assign sorts 09:15:36 Allowing 'multiple inheritance', in a condition, a Var occurrence x can eg be sorted as a Car and another occurrence x can eg be sorted as a Ship. If these a disjoint, the condition fails; if they have a non-empty intersection, eg AmphibiousVehicle, the sort of both x occurrences will be semantically specialized to that intersection. 09:15:36 michael: but different than classes 09:16:05 jos: to axel: sort can not be assigned to things 09:16:30 s/ a disjoint/ are disjoint/ 09:16:36 jos: whether we allow a sym to have different sorts or not? 09:16:47 michael: that is allowed 09:17:30 michael: now we are talking about declaring sorts: but that is not how it happens? 09:17:44 chris: we still don't know what you 09:17:51 mean by sort 09:18:18 Hassan: we might be confusing Symbols and Symbol-Occurances. Each Symbol can have multiple sorts, but each occurance has one sort. 09:18:31 hassan: this is a confusion of levevls: a symbol occurence has a single source 09:18:37 s/sort/source 09:19:00 hassan: a symbol can have more than one sort; an occurence just one 09:19:49 chris: what is the sort of f in f(a,b) 09:20:11 michael: signatures are different than sorts 09:20:58 chris: in the current syn everything is supposed to have a sort, right, and a signature. 09:21:05 Hassan, again we have that overloading: signature NAME s1 * ... * sn -> s , r1 * ... * rk -> r , ... 09:21:05 michael: yes 09:21:49 michael: (at the board) f^^foobar (that is how it is currently written) 09:22:43 michael: e.g. f^^xsd:string 09:24:08 Sandro: can you have "f"^^xsd:int ? 09:24:12 MichaelK: No. 09:25:10 markus: please use concrete sorts, not "foobar". how relevant is possibility of definition of new sort?s 09:25:29 michael: probably don't allow user defined in core 09:25:35 Michael: a symbol is really a pair like ("f", xsd:string) 09:26:11 Michael: Java has sorts, like in 123 is an integer. A datatype 09:26:16 markus: don't perceive sorts as classes. sorts are like datatypes in a prog. lang. 09:26:34 csma: but I understood sorts as more general as datatypes. 09:26:56 Markus: we should try to use concrete examples when talking about sorts, in order not to suggest using sorts in place of classes in knowledge representation. 09:27:22 csma: we declare types and sigs in another doc somewhere. when you use a var in a rule, you may declare its type 09:27:43 csma: const's type can always be retreived from its signature 09:27:53 Markus, do you mean we should initially have only 'primitive sorts', not 'user-defined sorts'? 09:28:25 csma: some types are in-built, but some can be defined by user (by reference to an external doc) 09:28:44 michael: get bcak to f(a.b) example 09:28:48 Re Harold. We should foresee user-defined sorts for extensions of RIF, but having a concrete list of primitiv sorts as a base is probably easier to understand 09:29:09 MichaelK: Sort in RIF Core should not be extensible -- they should NOT be for modeling knowledge. 09:29:12 michael: sorts will be fixed for the core. dialects might allow user-defined 09:29:26 +1 MichaelK 09:29:40 csma: remember we are talkng about language that exits 09:30:32 jos: we need sorts to distinguish to pred, const, vs. fcn symbols. sigs are not enough for that 09:30:37 Jos: we need sorts to distinguish between function symbols, constant symbols, predicate symbols. 09:30:39 +1 Jos 09:30:52 axel: we need sorts in rif core for "pred", etc 09:30:54 Hassan has joined #rif 09:31:12 chris: now I am worried that you axel agree with jos. 09:31:34 Chris: Most of our symbols will be of type URI -- whether they are predicate is another mechanism. 09:31:58 jos: we need sorts to fix the domain of interpretation 09:32:22 Markus, I agree, 'user-defined sorts' could be in a (future) dialect. MichaelK (on the whiteboard) also agrees to this. Why not right away reuse RDFS and OWL subClassOf sort hierarchies? 09:32:33 michael: there is no disjointness in core (between pred, fcns, etc) 09:32:55 axel: what does a = b mean then? 09:33:40 michael: sigs will take care of that 09:34:20 mdean, are you able to follow any of this? 09:34:32 (or hear it, I mean.) 09:34:56 gary: what is f in f(a,b)? 09:34:59 Re Harold: I do not think OWL classes are like sorts, I agree with Jos' view that sorts distinguish domains of interpretation (on a meta-semantic level). 09:35:05 Gary: so in f(a,b) is f of sort "string" or "function symbol" ? 09:35:22 yes - i can hear it fine 09:35:36 thanks 09:36:15 (We've had a couple loud airplanes overhead.) 09:36:37 i was wondering what that was 09:36:42 chris: typical case , e.g., P(a,y) where, most commonly <"P", rif:uri>, <"a", rif:uri>, <"y", xsd:string>. 09:37:03 Chris: P(a, ?y) => sorts <"p", rif:uri> ( <"a", rif:uri>, <"y", xsd:string> ) 09:37:05 chris: since P is a pred it will have a signature like... 09:37:44 Chris: P *also* has a signature: <"P", rif:uri> hasSignature rif:uri X xsd:string 09:37:59 michael: signature <"P", rif:uri> => rif:uri X xsd:string 09:38:25 Chris: P also has an extension { .... } "what populates the predicate" 09:38:54 (not in the syntax) 09:39:00 The distinction of function vs. predicate ( the top-level syntactical categories) could be made with namespaces or within the pathnames of sort webizing: .../function/unary/Int2Int vs. ../predicate/unary/Int. 09:39:02 chris: for vars, not in the syntax, they have binding associated 09:39:49 dave: did you really mean <"P", rif:uri> => rif:uri X xsd:string ? 09:40:04 DaveR: I expected the signature to be more like ( Person X TelephoneNumber ). The signature certainly shouldn't care about where the variable is. 09:40:21 chris: dave is saying this doesn't look like a sig of a pred. 09:40:41 michael: you can have several signatures.... 09:40:49 +1 DaveR 09:41:24 Markus and Jos, these 'levels' could be combined as I indicated with the namespaces and pathnames above. 09:41:31 csma: rif:uri could be associate with type "human" 09:41:37 chris: not 09:41:59 Chris: the signature of spouse is Person X Person 09:42:18 chris: take pred "spouse", sig would be person x person? 09:42:20 MichaelK: No, that, would be too much. 09:42:51 michael: sig wil be rif:uri x rif:uri 09:43:01 Chris, this could be indicated by ../predicate/binary/Spouse. 09:43:10 sandro: what about vars? 09:43:29 michael: <"x", xsd:string> 09:44:09 michael: which means it can only be bound to types of xsd:string 09:44:25 new scribe : john hall 09:44:59 MichaelK: what I mean by signature is much less than (Person X Person) stuff. 09:45:11 Harold, I fear that combining the levels yields confusion ("What exactly is a sort"-question) and possibly offers incompatible ways for modelling the same knowledge (you can refer to RDFS/OWL classes in RIF conditions [by some interoperability mechanism yet to be clarified]). I think RDFS/OWL interop should not come in via sorts. 09:46:10 Similarly, the function fatherOf could be sorted by .../function/unary/HumanToMale. Scribe: johnhall 09:46:33 csma: MK wouldtou retrict use of core only to the primitive sorts here? 09:47:03 I would. 09:48:13 hassan: what are signatures for p(1,x) and p("1",y) 09:48:37 Michael: xsd:string the two examples woul be illegal 09:49:11 Michael: With might have P with two signatures: string X string, int X int . Then P(1, ?X^^int) would be okay. 09:49:52 Axel: I think we want an untyped variable to be okay for any spot. 09:51:19 chrisw: are some variables not restricted? 09:51:33 Markus, we could *use* RDFS/OWL to define the sort lattice that we need, clearly announcing it as a reuse of the RDFS/OWL languages for our RIF content. 09:52:13 csma:what if O(int, int) but want to restrict ins to 1 100 09:52:24 ... e.g. if O is age 09:52:43 michaale: not so restricted 09:52:45 Harold, reusing RDF constructs on a language-level is always slightly problematic, since RDF is interpreted in a single model (the reused syntax parts cannot be seperated semantically from the object-level statements). 09:53:15 franc: in modeling langs, like to have datatypes, eg age 1 to 100 09:53:27 ... in prog langs,considered harmful 09:53:45 ... you will add ages 09:53:46 (Harold) So your RDFS-statements would appear semantically as part of your modelled domain and semantically interact unintentionally. 09:54:00 ... but will compute something that is not an age 09:54:21 (Harold) It is known that this design of RDF easily creates an inconsistent logic. 09:54:37 ... cannot have data tyoes with upper and lower bounds 09:54:37 ... and RIF will be a prog lang 09:54:50 chrisw: get back on track 09:55:06 ... DaveR are you clear on las q? 09:55:16 DaveR: only for simple case 09:55:23 Francois: things like age 0..100 make sense in schema languages, but not in programming languages (eg in computing averages, we sum the ages, and now go out of bounds.) 09:55:36 ... for more complex things, is rif iri a proxy 09:55:49 ... iri has lexical form, is not an object 09:56:13 chrisw: understand now that sorting mechanism is very coears grained 09:56:31 ... this is just adding a little more flexibility, but not much 09:56:34 Chris: signature for every rdf property is rdf:uri X rdf: uri [[ not true! ]] 09:56:42 .. and is not a userdefined notion 09:57:07 DaveR: couls use a balnk node or uri 09:57:20 Michael; existential variable 09:57:54 chrisw: trat blank noes as existential varianble 09:58:10 sandro: literals 09:58:27 chrisw: integer 1 does not have uri 09:58:33 sandro: it does 09:58:45 chrisw: integer has uri 09:59:11 josb; both interprested as same, varaiable ranges over domain 09:59:36 michael: someone has to say that this uri represents this integer 09:59:45 axel: so what is issue? 10:02:02 johnhall has joined #rif 10:02:11 Chris: would having a taxonomy of sorts, in which there is something more general, would that address your concern 10:02:14 Jos: yes. 10:02:26 Dave: I think, so but I'm not sure about rif:iri in this case. 10:02:32 franc: uri issue is difficult 10:02:35 Jos: both IRIs and various types of literals should be generalised by a more general "RDF resource" sort 10:03:00 ... programmer has to know that thing is unique id 10:03:13 ...alternative is to build in 10:03:51 franc; if we depart from RDF notion we have a problem 10:04:09 chrisw: not there yet but will be 10:04:52 hassan: what would be the sig of p (on whiteboard)? 10:05:11 chrisw: we are concerned just with lexical space 10:05:15 Markus, of course we have to be very careful the selecting the right sublanguage of RDFS (such as a 'fixed (layered) architectured' for defining a partial order) to the to avoid these problems, also liaising with the RDF group. Let's use my earlier example: AmphibiousVehicle subClassOf Car, Car subClassOf Vehicle, AmphibiousVehicle subClassOf Ship, Ship subClassOf Vehicle. 10:05:42 s/careful the/careful when/ 10:05:48 michael: sorts are meant to be primitove xml data types, with just a little more 10:06:02 ... paly with signatures to constrain 10:06:47 csma: what is rationale not to allow user defined sorts? 10:07:02 michael: mechanism of sorts in logic in limited 10:07:29 ... that of userdefined data types is needed 10:07:30 pvincent has joined #rif 10:07:39 Harold, I think this is a mine field that we can avoid by making such class hierarchies object-level statements. One can always write vehicle(X) :- Car(X) etc. to capture the same knowledge in RIF. I think this could be an easier solution that does not get us in touch with RDF semantics as part of our very core formalism. 10:07:50 ... want to do it dynamically 10:08:19 ... if syntactically correct, true or not is in application 10:08:39 chrisw: this is at syntactic level, not semantic 10:09:34 csma: if not part of RIF, why bother abouts sigs 10:09:44 michael: to support datatypes 10:10:01 csma: we just need to say that there are signatures 10:10:37 michael: we say that xsd strings are defined here, sigs elsehwere etc 10:11:22 csma: if I have arulethat uses a predicate Older, +int and +int applic specific 10:11:39 ... how does this relate to RIF abstract syntax? 10:11:56 Re MarkusK & Harold: in the current draft, we also have the frame part for doing this with # (typing terms) and ## (for building up type hierarchies) 10:12:16 Markus, would this mean you could hardly ever reuse the RDF/S language to encode even your simple taxonomies (partial orders) because of concerns regarding how this would scale up to the 'RDF/S full' semantics? 10:12:27 michael: will have signature signature P int X int, str X str 10:13:18 sandro: analogy with types in prog langs 10:13:25 michael: yes 10:13:34 Sandro: So this is like Java types, but NOT java classes. 10:13:43 ... primitive types, not complex 10:14:04 chrisw: does everyone understnd? 10:14:15 frac: not URI 10:14:39 Harold, I just think that solving RDFS interoperability is an important issue. It is just a very hard problem that our Core should not depend on. We will have a seperate action on how to exactly achieve (some level of) RDFS interoperability. But this need not be part of our Core sort mechanism. 10:14:45 michael: symbol of sort is string and name of sort 10:15:05 franc; when you speak of iri, do you mean a string? 10:15:34 MichaelK: IRIs are special strings. <"foo", rif:iri> is not the same as <"foo", xsd:string> The domain of interpretation for the first one is not fixed, where for the second one it is. 10:16:39 michael: symbols of type uri is well defined, but not interpretation could be mapped to anything 10:17:33 chrisw: for sematic web would ingnore source systems 10:17:56 ... but some rule languages need more 10:18:32 Chris: Does the semantic object (like the integer one) know about the things that refer to it, like "1"^^xsd:int and "http:..../1"^rif:iri ? 10:19:51 Markus, that's fine. So we'll need RIF Phases 2 and 3 to work with others in the Semantic Web Activity on the Big Semantic Web Language Convergence :-) 10:20:55 csma: do we want to forec every RIF dialect to do this type checking? 10:21:20 Sandro: Do we really want to say every RIF Core implementation has to do syntactic type checking like this? 10:21:28 markus: should be no problem to have semantic checks at the object level 10:22:29 Harold, I agree. Also to the fact that this might take until "Phase 3" -- that's why I would like to seperate it from the Core ;-) 10:23:00 MichaelK: You can ask: ?- P(?x^^int), ?x^^int=?y^^iri 10:23:02 DaveR: sort on a variable is a semantic restriction 10:23:19 Harold, Markus, for a proposal for RDFS interoperability, see http://lists.w3.org/Archives/Public/public-rif-wg/2007May/0077.html, http://lists.w3.org/Archives/Public/public-rif-wg/2007Jun/0002.html, 10:23:21 chrisw: this is just static 10:23:21 Chris: But java does static type checking on variables. 10:23:41 hassan: where do we draw the abstraction line? 10:23:48 We had discussion about the use of sorts in the thread following http://lists.w3.org/Archives/Public/public-rif-wg/2007May/0077.html 10:24:03 s/sorts/sorts in RDFS/ 10:24:04 axel: if we do this, we should call this "RIF schema" 10:24:07 Axel: call this RIF Schema -- because you'll want to re-use these schemas. 10:24:20 ... don't want to have to include this for every use 10:24:41 chrisw: get to basis solution before discussing variants 10:27:11 chrisw: are we all on the same poge for understanding signatues and sorts? 10:27:25 Chris: Now that I understand what this is, I consider this new enough information to reconsider whether to have this in core. 10:27:42 ... now that we understand, do we need it? 10:27:56 Axel, we discussed the option of a 'RIF Schema' language at the end of the previous session. To avoid competition on the schema or ontology level, this, then, led to the above RDFS/OWL reuse discussion Markus and I had on IRC. 10:28:29 Chris: How many people think we need this syntactic sorts & signatures mechanism in Core 10:29:37 11 yeses 10:29:48 3 no's 10:29:52 +1 unsure 10:30:32 hassan: at least this, but also support some of DaveR's concerns 10:31:29 chrisw: Dave, you don't need this, but if there were a mechanism to ignore ...? 10:31:54 DAveR: want it to be semantic 10:32:01 DaveR: builtins need to semantic domain checking, not this syntactic-level stuff. 10:32:10 ... not just my use, what we specify for library etc. 10:34:26 michael: when define built ins, do we want semantic checks? 10:34:48 ... if so cannot do it directly 10:35:19 ... if not, define that built ins will give run time errors 10:35:28 msinte1 has left #rif 10:35:45 Axel: I think dave rather talks about implicit cast sauff than "semantics", ie, whether some string in the lex space of integeer can be put as an argument of an int signature... Let's see at the discussion about conversion and casting whether that is so! 10:35:46 Michael: If we want SYNTACTIC checking (instead of run-time checking) then to add two numbers, one by URI, you'd need to do ?x^^int=uri, p(?x^^int, ...) 10:49:25 -Mike_Dean 11:09:52 josb_ has joined #rif 11:15:47 josb_ has joined #rif 11:17:40 agiurca has joined #rif 11:19:01 PaulaP has joined #rif 11:21:34 GiorgosStoilos has joined #rif 11:58:41 hello 12:00:59 CGI546-allen has joined #rif 12:01:11 ChrisW has joined #rif 12:01:31 msintek has joined #rif 12:01:57 +Mike_Dean 12:02:11 Hassan has joined #rif 12:02:27 AxelPolleres has joined #rif 12:02:44 DaveReynolds has joined #rif 12:03:04 IgorMozetic has joined #rif 12:03:55 MarkusK has joined #rif 12:04:02 scribenick: MarkusK 12:04:12 http://www.w3.org/2005/rules/wg/wiki/Arch/XML_Syntax 12:04:49 Scribe: Markus Kr�tzsch 12:05:11 agenda+ XML Schema from ASN 12:05:22 zakim, next item 12:05:22 agendum 3. "XML Schema from ASN" taken up [from ChrisW] 12:05:43 Gary: there should be as simple as possible rules for mapping from ASN to XML 12:06:24 ... subclasses as XML choice 12:07:42 Sandro: we may need more background on XSD to understand the details 12:11:45 Harold has joined #rif 12:12:09 Gary: leaf classes (w/o subclasses) are just elements (xsd:element). 12:12:28 ... classes with subclasses are references to groups. 12:14:16 References: example XSD http://www.w3.org/2005/rules/wg/wiki/Arch/XML_Syntax?action=AttachFile&do=get&target=RIF3.xsd and example instances http://www.w3.org/2005/rules/wg/wiki/Arch/XML_Syntax?action=AttachFile&do=get&target=RIF3.xml 12:15:06 csma: is it the right approach to have a short set of simple rules to translate ANS06 to XSD? We can still tweak the rules later. 12:15:21 Hassan: in general, yes. 12:16:10