Theory Ex2 (Isabelle2005: October 2005)

# Theory Ex2

Up to index of Isabelle/LCF/ex

theory Ex2
imports LCF
uses [Ex2.ML]
begin

    (* $Id: Ex2.thy,v 1.2 2005/09/03 15:54:11 wenzelm Exp $ *)

    header {* Example 3.8 *}

    theory Ex2
    imports LCF
    begin

    consts
      P     :: "'a => tr"
      F     :: "'a => 'a"
      G     :: "'a => 'a"
      H     :: "'a => 'b => 'b"
      K     :: "('a => 'b => 'b) => ('a => 'b => 'b)"

    axioms
      F_strict:     "F(UU) = UU"
      K:            "K = (%h x y. P(x) => y | F(h(G(x),y)))"
      H:            "H = FIX(K)"

    ML {* use_legacy_bindings (the_context ()) *}

    end

theorem example:

      ∀x. F(H(x, y)) = H(x, F(y))