src/HOL/W0/Maybe.ML
author nipkow
Thu, 24 Apr 1997 18:51:14 +0200
changeset 3044 3e3087aa69e7
parent 2520 aecaa76e7eff
child 3919 c036caebfc75
permissions -rw-r--r--
Updates because nat_ind_tac no longer appends "1" to the ind.var.
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
2520
aecaa76e7eff Incorporated Larry's changes.
nipkow
parents: 2518
diff changeset
     1
(* Title:     HOL/W0/Maybe.ML
aecaa76e7eff Incorporated Larry's changes.
nipkow
parents: 2518
diff changeset
     2
   ID:        $Id$
aecaa76e7eff Incorporated Larry's changes.
nipkow
parents: 2518
diff changeset
     3
   Author:    Dieter Nazareth and Tobias Nipkow
aecaa76e7eff Incorporated Larry's changes.
nipkow
parents: 2518
diff changeset
     4
   Copyright  1995 TU Muenchen
aecaa76e7eff Incorporated Larry's changes.
nipkow
parents: 2518
diff changeset
     5
*)
aecaa76e7eff Incorporated Larry's changes.
nipkow
parents: 2518
diff changeset
     6
2518
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
     7
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
     8
(* constructor laws for bind *)
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
     9
goalw thy [bind_def] "(Ok s) bind f = (f s)";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    10
by (Simp_tac 1);
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    11
qed "bind_Ok";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    12
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    13
goalw thy [bind_def] "Fail bind f = Fail";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    14
by (Simp_tac 1);
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    15
qed "bind_Fail";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    16
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    17
Addsimps [bind_Ok,bind_Fail];
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    18
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    19
(* expansion of bind *)
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    20
goal thy
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    21
  "P(res bind f) = ((res = Fail --> P Fail) & (!s. res = Ok s --> P(f s)))";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    22
by (maybe.induct_tac "res" 1);
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    23
by (fast_tac (HOL_cs addss !simpset) 1);
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    24
by (Asm_simp_tac 1);
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    25
qed "expand_bind";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    26
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    27
goal Maybe.thy
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    28
  "((m bind f) = Fail) = ((m=Fail) | (? p. m = Ok p & f p = Fail))";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    29
by (simp_tac (!simpset setloop (split_tac [expand_bind])) 1);
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    30
qed "bind_eq_Fail";
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    31
bee082efaa46 This is the old version og MiniML for the monomorphic case.
nipkow
parents:
diff changeset
    32
Addsimps [bind_eq_Fail];