src/HOL/Integ/Lagrange.thy
author wenzelm
Thu Jan 23 14:19:16 1997 +0100 (1997-01-23)
changeset 2545 d10abc8c11fb
parent 2281 e00c13a29eda
permissions -rw-r--r--
added AxClasses test;
     1 (*  Title:      HOL/Integ/Lagrange.thy
     2     ID:         $Id$
     3     Author:     Tobias Nipkow
     4     Copyright   1996 TU Muenchen
     5 
     6 
     7 This theory only contains a single thm, which is a lemma in Lagrange's proof
     8 that every natural number is the sum of 4 squares.  It's sole purpose is to
     9 demonstrate ordered rewriting for commutative rings.
    10 
    11 The enterprising reader might consider proving all of Lagrange's thm.
    12 *)
    13 Lagrange = Ring +
    14 
    15 constdefs sq :: 'a::times => 'a
    16          "sq x == x*x"
    17 
    18 end