Re: [open-axiom-devel] understanding domain vectors, optimization etc.,
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From: Gabriel D. R. <gd...@cs...> - 2008-05-25 20:07:12
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Martin Rubey <mar...@un...> writes: | Gabriel Dos Reis <gd...@cs...> writes: | | > Martin Rubey <mar...@un...> writes: | > | > | Gabriel Dos Reis <gd...@cs...> writes: | > | | > | > | Gaby, after some experiments, I could not find an example where "A add B", A | > | > | and B sharing representation, exports an operation from A instead of from B, | > | > | when the signature is present in both. | > | > | > | > That is basically what my oiriginal example was about -- | > | | > | Sorry, I don't understand. In the example below, the representations differ - | > | IndexedDirectProductAbelianGroup(R,S) is (I'd say) different from List | > | Pair(S,R). | > | > No, they have the same layout -- would you mind having a look at | > IndexedDirectProductAbelianGroup? | | I did. Only, I was thinking of IndexedDirectProductAbelianGroup(R,S) being | different from List Pair(S,R), because I did *not* identify | | IndexedDirectProductAbelianGroup(R,S) with Rep in | | Term:= Record(k:S,c:A) | Rep:= List Term yeah, a record with at most two elements is a cons -- otherwise it is a vector. A Pair is a cons. So we have list of conses. | > | I wonder whether this strange behaviour also occurs when the representations | > | are the same. | > | > I think I said yes in my previous message. Which point point isn't clear? | | Maybe I should have said, "when the representations are identical". | | But I admit that I didn't notice at first that the representations are, in some | sense, "compatible", and that this could be allowed. It is not just `compatible in some sense': The data representations are the same. Almost all of the algebra -- as currently written -- depend ciritcally on this identity principle. As ingrained in the `pretend' operator. -- Gaby |