| author | oheimb | 
| Thu, 24 Sep 1998 15:36:16 +0200 | |
| changeset 5548 | 5cd3396802f5 | 
| parent 5078 | 7b5ea59c0275 | 
| child 11375 | a6730c90e753 | 
| permissions | -rw-r--r-- | 
(* Title: HOL/Integ/Lagrange.thy ID: $Id$ Author: Tobias Nipkow Copyright 1996 TU Muenchen This theory only contains a single thm, which is a lemma in Lagrange's proof that every natural number is the sum of 4 squares. It's sole purpose is to demonstrate ordered rewriting for commutative rings. The enterprising reader might consider proving all of Lagrange's thm. *) Lagrange = Ring + constdefs sq :: 'a::times => 'a "sq x == x*x" end