diff -r e74f694ca1da -r c7a8f374339b src/HOL/MiniML/W.thy --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/HOL/MiniML/W.thy Wed Oct 25 09:46:46 1995 +0100 @@ -0,0 +1,28 @@ +(* Title: HOL/MiniML/W.thy + ID: $Id$ + Author: Dieter Nazareth and Tobias Nipkow + Copyright 1995 TU Muenchen + +Type inference algorithm W +*) + +W = MiniML + + +types + result_W = "(subst * type_expr * nat)maybe" + +(* type inference algorithm W *) +consts + W :: "[expr, type_expr list, nat] => result_W" + +primrec W expr + W_Var "W (Var i) a n = (if i < length a then Ok(id_subst, nth i a, n) + else Fail)" + W_Abs "W (Abs e) a n = W e ((TVar n)#a) (Suc n) bind + (%(s,t,m). Ok(s, Fun (s n) t, m) )" + W_App "W (App e1 e2) a n = + W e1 a n bind + (%(s1,t1,m1). W e2 ($ s1 a) m1 bind + (%(s2,t2,m2). mgu ($ s2 t1) (Fun t2 (TVar m2)) bind + (%u. Ok( ($ u) o (($ s2) o s1), $ u (TVar m2), Suc m2) )))" +end