Added a number of explicit type casts and delayed evaluations (all seemingly
needless) so that SML/NJ 110.9.1 would accept the importer...
(*  Title:      HOL/AxClasses/Semigroups.thy
    ID:         $Id$
    Author:     Markus Wenzel, TU Muenchen
    License:    GPL (GNU GENERAL PUBLIC LICENSE)
*)
theory Semigroups = Main:
consts
  times :: "'a => 'a => 'a"    (infixl "[*]" 70)
axclass semigroup < type
  assoc: "(x [*] y) [*] z = x [*] (y [*] z)"
consts
  plus :: "'a => 'a => 'a"    (infixl "[+]" 70)
axclass plus_semigroup < type
  assoc: "(x [+] y) [+] z = x [+] (y [+] z)"
end