src/HOL/MiniML/Maybe.ML
author paulson
Wed, 09 Oct 1996 13:32:33 +0200
changeset 2073 fb0655539d05
parent 2058 ff04984186e9
child 2525 477c05586286
permissions -rw-r--r--
New unified treatment of sequent calculi by Sara Kalvala combines the old LK and Modal with the new ILL (Int. Linear Logic)
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
1300
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     1
open Maybe;
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     2
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     3
(* constructor laws for bind *)
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     4
goalw thy [bind_def] "(Ok s) bind f = (f s)";
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     5
by (Simp_tac 1);
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     6
qed "bind_Ok";
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     7
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     8
goalw thy [bind_def] "Fail bind f = Fail";
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
     9
by (Simp_tac 1);
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    10
qed "bind_Fail";
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    11
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    12
Addsimps [bind_Ok,bind_Fail];
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    13
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    14
(* expansion of bind *)
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    15
goal thy
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    16
  "P(res bind f) = ((res = Fail --> P Fail) & (!s. res = Ok s --> P(f s)))";
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    17
by (maybe.induct_tac "res" 1);
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    18
by (fast_tac (HOL_cs addss !simpset) 1);
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    19
by (Asm_simp_tac 1);
c7a8f374339b New theory: type inference for let-free MiniML
nipkow
parents:
diff changeset
    20
qed "expand_bind";
1751
946efd210837 Added thm I_complete_wrt_W to I.
nipkow
parents: 1300
diff changeset
    21
1757
f7a573c46611 Added the second half of the W/I correspondence.
nipkow
parents: 1751
diff changeset
    22
goal Maybe.thy
f7a573c46611 Added the second half of the W/I correspondence.
nipkow
parents: 1751
diff changeset
    23
  "((m bind f) = Fail) = ((m=Fail) | (? p. m = Ok p & f p = Fail))";
2031
03a843f0f447 Ran expandshort
paulson
parents: 1757
diff changeset
    24
by (simp_tac (!simpset setloop (split_tac [expand_bind])) 1);
1757
f7a573c46611 Added the second half of the W/I correspondence.
nipkow
parents: 1751
diff changeset
    25
qed "bind_eq_Fail";
f7a573c46611 Added the second half of the W/I correspondence.
nipkow
parents: 1751
diff changeset
    26
f7a573c46611 Added the second half of the W/I correspondence.
nipkow
parents: 1751
diff changeset
    27
Addsimps [bind_eq_Fail];