(* Title: ZF/Let
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1995 University of Cambridge
Let expressions, and tuple pattern-matching (borrowed from HOL)
*)
Let = FOL +
types
letbinds letbind
consts
Let :: "['a::logic, 'a => 'b] => ('b::logic)"
syntax
"_bind" :: "[pttrn, 'a] => letbind" ("(2_ =/ _)" 10)
"" :: "letbind => letbinds" ("_")
"_binds" :: "[letbind, letbinds] => letbinds" ("_;/ _")
"_Let" :: "[letbinds, 'a] => 'a" ("(let (_)/ in (_))" 10)
translations
"_Let(_binds(b, bs), e)" == "_Let(b, _Let(bs, e))"
"let x = a in e" == "Let(a, %x. e)"
defs
Let_def "Let(s, f) == f(s)"
end