src/HOL/AxClasses/Tutorial/ProductInsts.thy
author nipkow
Tue, 23 Jun 1998 18:07:45 +0200
changeset 5071 548f398d770b
parent 1247 18b1441fb603
permissions -rw-r--r--
Consequences of the change from [ := ] to ( := ) in theory Update.

(*  Title:      HOL/AxClasses/Tutorial/ProductInsts.thy
    ID:         $Id$
    Author:     Markus Wenzel, TU Muenchen

Instantiate the 'syntactic' class "product", then define "<*>" on type
"bool".

Note: This may look like Haskell-instance, but is not quite the same!
*)

ProductInsts = Product +

instance
  bool :: product

defs
  prod_bool_def "x <*> y  == x & y::bool"

end