Re: How we say Same literals

 

     Le Samedi 27 décembre 2014 16h44, Bijan Parsia <bijan.parsia@manchester.ac.uk> a écrit :
   

 And?
Structural equivalence is different than equality. Hence the name "structural equivalence". 
Two axioms may be structurally inequivalent while being logically equivalent. 
I can't really figure out what your goals are so quoting bits of spec is not exactly illuminating to me. 
If your question is "when are two data values identical" then the answer is "when they are the same value".
If your question is when do two structurally inequivalent data value expressions denote the same value, the answer is "when the lexical to value mapping of the associate datatypes returns the same element of the value space". This happens all the time (see my earlier example). 
If the question is when are two non-identical values equal then the answer is "generally they are not, but you can have a theory of equality or an equivalence relation where they are; these aren't available in owl, but eg sparql comparators sometimes involve type coercsion". 
May this what I want. I tried several cases with protegé. But what i briefly want to to state that we have two distinct literals.(However i would like to further explain for the reader...whey they are distinct... Is it problem of disjointess of datatypes...is is problem of lexical form... or what...Hope this helps!
Thank you for your serous help.
On Dec 27, 2014, at 10:31, "Leila Bayoudhi" <bayoudhileila@yahoo.fr> wrote:


Hi, here is what I find in "RDF Literal Data Types in Practice":"""OWL follows similar equality rules, declaring “Two literals are structurally equivalentif and only if both the lexical form and the data type are structurallyequivalent; that is, literals denoting the same data value are structurallydifferent if either their lexical form or the data type is different.”"""[RDF Literal Data Types in Practice]

Le Samedi 27 décembre 2014 15h09, Bijan Parsia <bijan.parsia@manchester.ac.uk> a écrit :


I'm also not sure what you want specifically. 

We know, by the predefined disjointness of the types that the values must be distinct and by the functionality that we must have only one successor. By the distinctness, we have two. Contradiction.

If you are trying to illustrate how values carry identity conditions, I wouldn't use values from disjoint types, but merely different values from the same type eg 1 and 2.

If you are trying to show that lexical form is datatype sensitive then yeah using same lexical form and disjoint datatype will do the trick.

Cheers,
Bijan.