(* Title: HOL/Hoare/HeapSyntax.thy
Author: Tobias Nipkow
Copyright 2002 TUM
*)
theory HeapSyntax imports Hoare_Logic Heap begin
subsection "Field access and update"
syntax
"_refupdate" :: "('a \<Rightarrow> 'b) \<Rightarrow> 'a ref \<Rightarrow> 'b \<Rightarrow> ('a \<Rightarrow> 'b)"
("_/'((_ \<rightarrow> _)')" [1000,0] 900)
"_fassign" :: "'a ref => id => 'v => 's com"
("(2_^._ :=/ _)" [70,1000,65] 61)
"_faccess" :: "'a ref => ('a ref \<Rightarrow> 'v) => 'v"
("_^._" [65,1000] 65)
translations
"f(r \<rightarrow> v)" == "f(CONST addr r := v)"
"p^.f := e" => "f := f(p \<rightarrow> e)"
"p^.f" => "f(CONST addr p)"
declare fun_upd_apply[simp del] fun_upd_same[simp] fun_upd_other[simp]
text "An example due to Suzuki:"
lemma "VARS v n
{w = Ref w0 & x = Ref x0 & y = Ref y0 & z = Ref z0 &
distinct[w0,x0,y0,z0]}
w^.v := (1::int); w^.n := x;
x^.v := 2; x^.n := y;
y^.v := 3; y^.n := z;
z^.v := 4; x^.n := z
{w^.n^.n^.v = 4}"
by vcg_simp
end