author | paulson |
Tue, 16 Jul 1996 15:49:46 +0200 | |
changeset 1868 | 836950047d85 |
parent 1247 | 18b1441fb603 |
child 2907 | 0e272e4c7cb2 |
permissions | -rw-r--r-- |
(* Title: Group.thy ID: $Id$ Author: Markus Wenzel, TU Muenchen *) Group = Sigs + Set + (* semigroups *) axclass semigroup < times assoc "(x * y) * z = x * (y * z)" (* groups *) axclass group < one, inv, semigroup left_unit "1 * x = x" left_inv "inv x * x = 1" (* abelian groups *) axclass agroup < group commut "x * y = y * x" end