author | haftmann |
Mon, 08 Feb 2010 17:12:22 +0100 | |
changeset 35045 | a77d200e6503 |
parent 31023 | d027411c9a38 |
child 38715 | 6513ea67d95d |
permissions | -rw-r--r-- |
23152 | 1 |
(* Title: HOLCF/Tools/cont_proc.ML |
2 |
Author: Brian Huffman |
|
3 |
*) |
|
4 |
||
5 |
signature CONT_PROC = |
|
6 |
sig |
|
7 |
val is_lcf_term: term -> bool |
|
8 |
val cont_thms: term -> thm list |
|
9 |
val all_cont_thms: term -> thm list |
|
29662 | 10 |
val cont_tac: int -> tactic |
23152 | 11 |
val cont_proc: theory -> simproc |
12 |
val setup: theory -> theory |
|
13 |
end; |
|
14 |
||
31023 | 15 |
structure ContProc :> CONT_PROC = |
23152 | 16 |
struct |
17 |
||
18 |
(** theory context references **) |
|
19 |
||
29047 | 20 |
val cont_K = @{thm cont_const}; |
21 |
val cont_I = @{thm cont_id}; |
|
22 |
val cont_A = @{thm cont2cont_Rep_CFun}; |
|
23 |
val cont_L = @{thm cont2cont_LAM}; |
|
24 |
val cont_R = @{thm cont_Rep_CFun2}; |
|
23152 | 25 |
|
26 |
(* checks whether a term contains no dangling bound variables *) |
|
29372 | 27 |
fun is_closed_term t = not (Term.loose_bvar (t, 0)); |
23152 | 28 |
|
29 |
(* checks whether a term is written entirely in the LCF sublanguage *) |
|
29047 | 30 |
fun is_lcf_term (Const (@{const_name Rep_CFun}, _) $ t $ u) = |
23152 | 31 |
is_lcf_term t andalso is_lcf_term u |
29047 | 32 |
| is_lcf_term (Const (@{const_name Abs_CFun}, _) $ Abs (_, _, t)) = |
33 |
is_lcf_term t |
|
29373 | 34 |
| is_lcf_term (Const (@{const_name Abs_CFun}, _) $ t) = |
35 |
is_lcf_term (Term.incr_boundvars 1 t $ Bound 0) |
|
23152 | 36 |
| is_lcf_term (Bound _) = true |
37 |
| is_lcf_term t = is_closed_term t; |
|
38 |
||
39 |
(* |
|
40 |
efficiently generates a cont thm for every LAM abstraction in a term, |
|
41 |
using forward proof and reusing common subgoals |
|
42 |
*) |
|
43 |
local |
|
44 |
fun var 0 = [SOME cont_I] |
|
45 |
| var n = NONE :: var (n-1); |
|
46 |
||
47 |
fun k NONE = cont_K |
|
48 |
| k (SOME x) = x; |
|
49 |
||
50 |
fun ap NONE NONE = NONE |
|
51 |
| ap x y = SOME (k y RS (k x RS cont_A)); |
|
52 |
||
53 |
fun zip [] [] = [] |
|
54 |
| zip [] (y::ys) = (ap NONE y ) :: zip [] ys |
|
55 |
| zip (x::xs) [] = (ap x NONE) :: zip xs [] |
|
56 |
| zip (x::xs) (y::ys) = (ap x y ) :: zip xs ys |
|
57 |
||
58 |
fun lam [] = ([], cont_K) |
|
59 |
| lam (x::ys) = |
|
60 |
let |
|
29371 | 61 |
(* should use "close_derivation" for thms that are used multiple times *) |
23152 | 62 |
(* it seems to allow for sharing in explicit proof objects *) |
29371 | 63 |
val x' = Thm.close_derivation (k x); |
23152 | 64 |
val Lx = x' RS cont_L; |
65 |
in (map (fn y => SOME (k y RS Lx)) ys, x') end; |
|
66 |
||
67 |
(* first list: cont thm for each dangling bound variable *) |
|
68 |
(* second list: cont thm for each LAM in t *) |
|
69 |
(* if b = false, only return cont thm for outermost LAMs *) |
|
29047 | 70 |
fun cont_thms1 b (Const (@{const_name Rep_CFun}, _) $ f $ t) = |
23152 | 71 |
let |
72 |
val (cs1,ls1) = cont_thms1 b f; |
|
73 |
val (cs2,ls2) = cont_thms1 b t; |
|
74 |
in (zip cs1 cs2, if b then ls1 @ ls2 else []) end |
|
29047 | 75 |
| cont_thms1 b (Const (@{const_name Abs_CFun}, _) $ Abs (_, _, t)) = |
23152 | 76 |
let |
77 |
val (cs, ls) = cont_thms1 b t; |
|
78 |
val (cs', l) = lam cs; |
|
79 |
in (cs', l::ls) end |
|
29373 | 80 |
| cont_thms1 b (Const (@{const_name Abs_CFun}, _) $ t) = |
81 |
let |
|
82 |
val t' = Term.incr_boundvars 1 t $ Bound 0; |
|
83 |
val (cs, ls) = cont_thms1 b t'; |
|
84 |
val (cs', l) = lam cs; |
|
85 |
in (cs', l::ls) end |
|
23152 | 86 |
| cont_thms1 _ (Bound n) = (var n, []) |
87 |
| cont_thms1 _ _ = ([], []); |
|
88 |
in |
|
89 |
(* precondition: is_lcf_term t = true *) |
|
90 |
fun cont_thms t = snd (cont_thms1 false t); |
|
91 |
fun all_cont_thms t = snd (cont_thms1 true t); |
|
92 |
end; |
|
93 |
||
94 |
(* |
|
95 |
Given the term "cont f", the procedure tries to construct the |
|
96 |
theorem "cont f == True". If this theorem cannot be completely |
|
97 |
solved by the introduction rules, then the procedure returns a |
|
98 |
conditional rewrite rule with the unsolved subgoals as premises. |
|
99 |
*) |
|
100 |
||
29662 | 101 |
val cont_tac = |
29048
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
102 |
let |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
103 |
val rules = [cont_K, cont_I, cont_R, cont_A, cont_L]; |
23152 | 104 |
|
29662 | 105 |
fun new_cont_tac f' i = |
29048
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
106 |
case all_cont_thms f' of |
29662 | 107 |
[] => no_tac |
108 |
| (c::cs) => rtac c i; |
|
23152 | 109 |
|
29048
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
110 |
fun cont_tac_of_term (Const (@{const_name cont}, _) $ f) = |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
111 |
let |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
112 |
val f' = Const (@{const_name Abs_CFun}, dummyT) $ f; |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
113 |
in |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
114 |
if is_lcf_term f' |
29662 | 115 |
then new_cont_tac f' |
29048
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
116 |
else REPEAT_ALL_NEW (resolve_tac rules) |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
117 |
end |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
118 |
| cont_tac_of_term _ = K no_tac; |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
119 |
in |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
120 |
SUBGOAL (fn (t, i) => |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
121 |
cont_tac_of_term (HOLogic.dest_Trueprop t) i) |
0735d0f89172
implement cont_proc theorem cache using theory data
huffman
parents:
29047
diff
changeset
|
122 |
end; |
23152 | 123 |
|
124 |
local |
|
125 |
fun solve_cont thy _ t = |
|
126 |
let |
|
127 |
val tr = instantiate' [] [SOME (cterm_of thy t)] Eq_TrueI; |
|
29662 | 128 |
in Option.map fst (Seq.pull (cont_tac 1 tr)) end |
23152 | 129 |
in |
130 |
fun cont_proc thy = |
|
131 |
Simplifier.simproc thy "cont_proc" ["cont f"] solve_cont; |
|
132 |
end; |
|
133 |
||
26496
49ae9456eba9
purely functional setup of claset/simpset/clasimpset;
wenzelm
parents:
24043
diff
changeset
|
134 |
fun setup thy = Simplifier.map_simpset (fn ss => ss addsimprocs [cont_proc thy]) thy; |
23152 | 135 |
|
136 |
end; |