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* Numbers: some improvements in proofsGravatar letouzey2011-01-03
| | | | | | | | | | - a ltac solve_proper which generalizes solve_predicate_wd and co - using le_elim is nicer that (apply le_lteq; destruct ...) - "apply ->" can now be "apply" most of the time. Benefit: NumPrelude is now almost empty git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@13762 85f007b7-540e-0410-9357-904b9bb8a0f7
* Cosmetic : let's take advantage of the n-ary exists notationGravatar letouzey2010-12-17
| | | | git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@13721 85f007b7-540e-0410-9357-904b9bb8a0f7
* Integer division: quot and rem (trunc convention) in addition to div and modGravatar letouzey2010-11-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (floor convention). We follow Haskell naming convention: quot and rem are for Round-Toward-Zero (a.k.a Trunc, what Ocaml, C, Asm do by default, cf. the ex-ZOdiv file), while div and mod are for Round-Toward-Bottom (a.k.a Floor, what Coq does historically in Zdiv). We use unicode รท for quot, and infix rem for rem (which is actually remainder in full). This way, both conventions can be used at the same time. Definitions (and proofs of specifications) for div mod quot rem are migrated in a new file Zdiv_def. Ex-ZOdiv file is now Zquot. With this new organisation, no need for functor application in Zdiv and Zquot. On the abstract side, ZAxiomsSig now provides div mod quot rem. Zproperties now contains properties of them. In NZDiv, we stop splitting specifications in Common vs. Specific parts. Instead, the NZ specification is be extended later, even if this leads to a useless mod_bound_pos, subsumed by more precise axioms. A few results in ZDivTrunc and ZDivFloor are improved (sgn stuff). A few proofs in Nnat, Znat, Zabs are reworked (no more dependency to Zmin, Zmax). A lcm (least common multiple) is derived abstractly from gcd and division (and hence available for nat N BigN Z BigZ :-). In these new files NLcm and ZLcm, we also provide some combined properties of div mod quot rem gcd. We also provide a new file Zeuclid implementing a third division convention, where the remainder is always positive. This file instanciate the abstract one ZDivEucl. Operation names are ZEuclid.div and ZEuclid.modulo. git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@13633 85f007b7-540e-0410-9357-904b9bb8a0f7
* Numbers: axiomatization, properties and implementations of gcdGravatar letouzey2010-11-05
- For nat, we create a brand-new gcd function, structural in the sense of Coq, even if it's Euclid algorithm. Cool... - We re-organize the Zgcd that was in Znumtheory, create out of it files Pgcd, Ngcd_def, Zgcd_def. Proofs of correctness are revised in order to be much simpler (no omega, no advanced lemmas of Znumtheory, etc). - Abstract Properties NZGcd / ZGcd / NGcd could still be completed, for the moment they contain up to Gauss thm. We could add stuff about (relative) primality, relationship between gcd and div,mod, or stuff about parity, etc etc. - Znumtheory remains as it was, apart for Zgcd and correctness proofs gone elsewhere. We could later take advantage of ZGcd in it. Someday, we'll have to switch from the current Zdivide inductive, to Zdivide' via exists. To be continued... git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@13623 85f007b7-540e-0410-9357-904b9bb8a0f7