src/CCL/set.ML
 author paulson Mon Dec 07 18:26:25 1998 +0100 (1998-12-07) changeset 6019 0e55c2fb2ebb parent 8 c3d2c6dcf3f0 permissions -rw-r--r--
tidying
```     1 (*  Title: 	set/set
```
```     2     ID:         \$Id\$
```
```     3
```
```     4 For set.thy.
```
```     5
```
```     6 Modified version of
```
```     7     Title: 	HOL/set
```
```     8     Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
```
```     9     Copyright   1991  University of Cambridge
```
```    10
```
```    11 For set.thy.  Set theory for higher-order logic.  A set is simply a predicate.
```
```    12 *)
```
```    13
```
```    14 open Set;
```
```    15
```
```    16 val [prem] = goal Set.thy "[| P(a) |] ==> a : {x.P(x)}";
```
```    17 by (rtac (mem_Collect_iff RS iffD2) 1);
```
```    18 by (rtac prem 1);
```
```    19 val CollectI = result();
```
```    20
```
```    21 val prems = goal Set.thy "[| a : {x.P(x)} |] ==> P(a)";
```
```    22 by (resolve_tac (prems RL [mem_Collect_iff  RS iffD1]) 1);
```
```    23 val CollectD = result();
```
```    24
```
```    25 val CollectE = make_elim CollectD;
```
```    26
```
```    27 val [prem] = goal Set.thy "[| !!x. x:A <-> x:B |] ==> A = B";
```
```    28 by (rtac (set_extension RS iffD2) 1);
```
```    29 by (rtac (prem RS allI) 1);
```
```    30 val set_ext = result();
```
```    31
```
```    32 (*** Bounded quantifiers ***)
```
```    33
```
```    34 val prems = goalw Set.thy [Ball_def]
```
```    35     "[| !!x. x:A ==> P(x) |] ==> ALL x:A. P(x)";
```
```    36 by (REPEAT (ares_tac (prems @ [allI,impI]) 1));
```
```    37 val ballI = result();
```
```    38
```
```    39 val [major,minor] = goalw Set.thy [Ball_def]
```
```    40     "[| ALL x:A. P(x);  x:A |] ==> P(x)";
```
```    41 by (rtac (minor RS (major RS spec RS mp)) 1);
```
```    42 val bspec = result();
```
```    43
```
```    44 val major::prems = goalw Set.thy [Ball_def]
```
```    45     "[| ALL x:A. P(x);  P(x) ==> Q;  ~ x:A ==> Q |] ==> Q";
```
```    46 by (rtac (major RS spec RS impCE) 1);
```
```    47 by (REPEAT (eresolve_tac prems 1));
```
```    48 val ballE = result();
```
```    49
```
```    50 (*Takes assumptions ALL x:A.P(x) and a:A; creates assumption P(a)*)
```
```    51 fun ball_tac i = etac ballE i THEN contr_tac (i+1);
```
```    52
```
```    53 val prems = goalw Set.thy [Bex_def]
```
```    54     "[| P(x);  x:A |] ==> EX x:A. P(x)";
```
```    55 by (REPEAT (ares_tac (prems @ [exI,conjI]) 1));
```
```    56 val bexI = result();
```
```    57
```
```    58 val bexCI = prove_goal Set.thy
```
```    59    "[| EX x:A. ~P(x) ==> P(a);  a:A |] ==> EX x:A.P(x)"
```
```    60  (fn prems=>
```
```    61   [ (rtac classical 1),
```
```    62     (REPEAT (ares_tac (prems@[bexI,ballI,notI,notE]) 1))  ]);
```
```    63
```
```    64 val major::prems = goalw Set.thy [Bex_def]
```
```    65     "[| EX x:A. P(x);  !!x. [| x:A; P(x) |] ==> Q  |] ==> Q";
```
```    66 by (rtac (major RS exE) 1);
```
```    67 by (REPEAT (eresolve_tac (prems @ [asm_rl,conjE]) 1));
```
```    68 val bexE = result();
```
```    69
```
```    70 (*Trival rewrite rule;   (! x:A.P)=P holds only if A is nonempty!*)
```
```    71 val prems = goal Set.thy
```
```    72     "(ALL x:A. True) <-> True";
```
```    73 by (REPEAT (ares_tac [TrueI,ballI,iffI] 1));
```
```    74 val ball_rew = result();
```
```    75
```
```    76 (** Congruence rules **)
```
```    77
```
```    78 val prems = goal Set.thy
```
```    79     "[| A=A';  !!x. x:A' ==> P(x) <-> P'(x) |] ==> \
```
```    80 \    (ALL x:A. P(x)) <-> (ALL x:A'. P'(x))";
```
```    81 by (resolve_tac (prems RL [ssubst,iffD2]) 1);
```
```    82 by (REPEAT (ares_tac [ballI,iffI] 1
```
```    83      ORELSE eresolve_tac ([make_elim bspec, mp] @ (prems RL [iffE])) 1));
```
```    84 val ball_cong = result();
```
```    85
```
```    86 val prems = goal Set.thy
```
```    87     "[| A=A';  !!x. x:A' ==> P(x) <-> P'(x) |] ==> \
```
```    88 \    (EX x:A. P(x)) <-> (EX x:A'. P'(x))";
```
```    89 by (resolve_tac (prems RL [ssubst,iffD2]) 1);
```
```    90 by (REPEAT (etac bexE 1
```
```    91      ORELSE ares_tac ([bexI,iffI] @ (prems RL [iffD1,iffD2])) 1));
```
```    92 val bex_cong = result();
```
```    93
```
```    94 (*** Rules for subsets ***)
```
```    95
```
```    96 val prems = goalw Set.thy [subset_def] "(!!x.x:A ==> x:B) ==> A <= B";
```
```    97 by (REPEAT (ares_tac (prems @ [ballI]) 1));
```
```    98 val subsetI = result();
```
```    99
```
```   100 (*Rule in Modus Ponens style*)
```
```   101 val major::prems = goalw Set.thy [subset_def] "[| A <= B;  c:A |] ==> c:B";
```
```   102 by (rtac (major RS bspec) 1);
```
```   103 by (resolve_tac prems 1);
```
```   104 val subsetD = result();
```
```   105
```
```   106 (*Classical elimination rule*)
```
```   107 val major::prems = goalw Set.thy [subset_def]
```
```   108     "[| A <= B;  ~(c:A) ==> P;  c:B ==> P |] ==> P";
```
```   109 by (rtac (major RS ballE) 1);
```
```   110 by (REPEAT (eresolve_tac prems 1));
```
```   111 val subsetCE = result();
```
```   112
```
```   113 (*Takes assumptions A<=B; c:A and creates the assumption c:B *)
```
```   114 fun set_mp_tac i = etac subsetCE i  THEN  mp_tac i;
```
```   115
```
```   116 val subset_refl = prove_goal Set.thy "A <= A"
```
```   117  (fn _=> [ (REPEAT (ares_tac [subsetI] 1)) ]);
```
```   118
```
```   119 goal Set.thy "!!A B C. [| A<=B;  B<=C |] ==> A<=C";
```
```   120 br subsetI 1;
```
```   121 by (REPEAT (eresolve_tac [asm_rl, subsetD] 1));
```
```   122 val subset_trans = result();
```
```   123
```
```   124
```
```   125 (*** Rules for equality ***)
```
```   126
```
```   127 (*Anti-symmetry of the subset relation*)
```
```   128 val prems = goal Set.thy "[| A <= B;  B <= A |] ==> A = B";
```
```   129 by (rtac (iffI RS set_ext) 1);
```
```   130 by (REPEAT (ares_tac (prems RL [subsetD]) 1));
```
```   131 val subset_antisym = result();
```
```   132 val equalityI = subset_antisym;
```
```   133
```
```   134 (* Equality rules from ZF set theory -- are they appropriate here? *)
```
```   135 val prems = goal Set.thy "A = B ==> A<=B";
```
```   136 by (resolve_tac (prems RL [subst]) 1);
```
```   137 by (rtac subset_refl 1);
```
```   138 val equalityD1 = result();
```
```   139
```
```   140 val prems = goal Set.thy "A = B ==> B<=A";
```
```   141 by (resolve_tac (prems RL [subst]) 1);
```
```   142 by (rtac subset_refl 1);
```
```   143 val equalityD2 = result();
```
```   144
```
```   145 val prems = goal Set.thy
```
```   146     "[| A = B;  [| A<=B; B<=A |] ==> P |]  ==>  P";
```
```   147 by (resolve_tac prems 1);
```
```   148 by (REPEAT (resolve_tac (prems RL [equalityD1,equalityD2]) 1));
```
```   149 val equalityE = result();
```
```   150
```
```   151 val major::prems = goal Set.thy
```
```   152     "[| A = B;  [| c:A; c:B |] ==> P;  [| ~ c:A; ~ c:B |] ==> P |]  ==>  P";
```
```   153 by (rtac (major RS equalityE) 1);
```
```   154 by (REPEAT (contr_tac 1 ORELSE eresolve_tac ([asm_rl,subsetCE]@prems) 1));
```
```   155 val equalityCE = result();
```
```   156
```
```   157 (*Lemma for creating induction formulae -- for "pattern matching" on p
```
```   158   To make the induction hypotheses usable, apply "spec" or "bspec" to
```
```   159   put universal quantifiers over the free variables in p. *)
```
```   160 val prems = goal Set.thy
```
```   161     "[| p:A;  !!z. z:A ==> p=z --> R |] ==> R";
```
```   162 by (rtac mp 1);
```
```   163 by (REPEAT (resolve_tac (refl::prems) 1));
```
```   164 val setup_induction = result();
```
```   165
```
```   166 goal Set.thy "{x.x:A} = A";
```
```   167 by (REPEAT (ares_tac [equalityI,subsetI,CollectI] 1  ORELSE eresolve_tac [CollectD] 1));
```
```   168 val trivial_set = result();
```
```   169
```
```   170 (*** Rules for binary union -- Un ***)
```
```   171
```
```   172 val prems = goalw Set.thy [Un_def] "c:A ==> c : A Un B";
```
```   173 by (REPEAT (resolve_tac (prems @ [CollectI,disjI1]) 1));
```
```   174 val UnI1 = result();
```
```   175
```
```   176 val prems = goalw Set.thy [Un_def] "c:B ==> c : A Un B";
```
```   177 by (REPEAT (resolve_tac (prems @ [CollectI,disjI2]) 1));
```
```   178 val UnI2 = result();
```
```   179
```
```   180 (*Classical introduction rule: no commitment to A vs B*)
```
```   181 val UnCI = prove_goal Set.thy "(~c:B ==> c:A) ==> c : A Un B"
```
```   182  (fn prems=>
```
```   183   [ (rtac classical 1),
```
```   184     (REPEAT (ares_tac (prems@[UnI1,notI]) 1)),
```
```   185     (REPEAT (ares_tac (prems@[UnI2,notE]) 1)) ]);
```
```   186
```
```   187 val major::prems = goalw Set.thy [Un_def]
```
```   188     "[| c : A Un B;  c:A ==> P;  c:B ==> P |] ==> P";
```
```   189 by (rtac (major RS CollectD RS disjE) 1);
```
```   190 by (REPEAT (eresolve_tac prems 1));
```
```   191 val UnE = result();
```
```   192
```
```   193
```
```   194 (*** Rules for small intersection -- Int ***)
```
```   195
```
```   196 val prems = goalw Set.thy [Int_def]
```
```   197     "[| c:A;  c:B |] ==> c : A Int B";
```
```   198 by (REPEAT (resolve_tac (prems @ [CollectI,conjI]) 1));
```
```   199 val IntI = result();
```
```   200
```
```   201 val [major] = goalw Set.thy [Int_def] "c : A Int B ==> c:A";
```
```   202 by (rtac (major RS CollectD RS conjunct1) 1);
```
```   203 val IntD1 = result();
```
```   204
```
```   205 val [major] = goalw Set.thy [Int_def] "c : A Int B ==> c:B";
```
```   206 by (rtac (major RS CollectD RS conjunct2) 1);
```
```   207 val IntD2 = result();
```
```   208
```
```   209 val [major,minor] = goal Set.thy
```
```   210     "[| c : A Int B;  [| c:A; c:B |] ==> P |] ==> P";
```
```   211 by (rtac minor 1);
```
```   212 by (rtac (major RS IntD1) 1);
```
```   213 by (rtac (major RS IntD2) 1);
```
```   214 val IntE = result();
```
```   215
```
```   216
```
```   217 (*** Rules for set complement -- Compl ***)
```
```   218
```
```   219 val prems = goalw Set.thy [Compl_def]
```
```   220     "[| c:A ==> False |] ==> c : Compl(A)";
```
```   221 by (REPEAT (ares_tac (prems @ [CollectI,notI]) 1));
```
```   222 val ComplI = result();
```
```   223
```
```   224 (*This form, with negated conclusion, works well with the Classical prover.
```
```   225   Negated assumptions behave like formulae on the right side of the notional
```
```   226   turnstile...*)
```
```   227 val major::prems = goalw Set.thy [Compl_def]
```
```   228     "[| c : Compl(A) |] ==> ~c:A";
```
```   229 by (rtac (major RS CollectD) 1);
```
```   230 val ComplD = result();
```
```   231
```
```   232 val ComplE = make_elim ComplD;
```
```   233
```
```   234
```
```   235 (*** Empty sets ***)
```
```   236
```
```   237 goalw Set.thy [empty_def] "{x.False} = {}";
```
```   238 br refl 1;
```
```   239 val empty_eq = result();
```
```   240
```
```   241 val [prem] = goalw Set.thy [empty_def] "a : {} ==> P";
```
```   242 by (rtac (prem RS CollectD RS FalseE) 1);
```
```   243 val emptyD = result();
```
```   244
```
```   245 val emptyE = make_elim emptyD;
```
```   246
```
```   247 val [prem] = goal Set.thy "~ A={} ==> (EX x.x:A)";
```
```   248 br (prem RS swap) 1;
```
```   249 br equalityI 1;
```
```   250 by (ALLGOALS (fast_tac (FOL_cs addSIs [subsetI] addSEs [emptyD])));
```
```   251 val not_emptyD = result();
```
```   252
```
```   253 (*** Singleton sets ***)
```
```   254
```
```   255 goalw Set.thy [singleton_def] "a : {a}";
```
```   256 by (rtac CollectI 1);
```
```   257 by (rtac refl 1);
```
```   258 val singletonI = result();
```
```   259
```
```   260 val [major] = goalw Set.thy [singleton_def] "b : {a} ==> b=a";
```
```   261 by (rtac (major RS CollectD) 1);
```
```   262 val singletonD = result();
```
```   263
```
```   264 val singletonE = make_elim singletonD;
```
```   265
```
```   266 (*** Unions of families ***)
```
```   267
```
```   268 (*The order of the premises presupposes that A is rigid; b may be flexible*)
```
```   269 val prems = goalw Set.thy [UNION_def]
```
```   270     "[| a:A;  b: B(a) |] ==> b: (UN x:A. B(x))";
```
```   271 by (REPEAT (resolve_tac (prems @ [bexI,CollectI]) 1));
```
```   272 val UN_I = result();
```
```   273
```
```   274 val major::prems = goalw Set.thy [UNION_def]
```
```   275     "[| b : (UN x:A. B(x));  !!x.[| x:A;  b: B(x) |] ==> R |] ==> R";
```
```   276 by (rtac (major RS CollectD RS bexE) 1);
```
```   277 by (REPEAT (ares_tac prems 1));
```
```   278 val UN_E = result();
```
```   279
```
```   280 val prems = goal Set.thy
```
```   281     "[| A=B;  !!x. x:B ==> C(x) = D(x) |] ==> \
```
```   282 \    (UN x:A. C(x)) = (UN x:B. D(x))";
```
```   283 by (REPEAT (etac UN_E 1
```
```   284      ORELSE ares_tac ([UN_I,equalityI,subsetI] @
```
```   285 		      (prems RL [equalityD1,equalityD2] RL [subsetD])) 1));
```
```   286 val UN_cong = result();
```
```   287
```
```   288 (*** Intersections of families -- INTER x:A. B(x) is Inter(B)``A ) *)
```
```   289
```
```   290 val prems = goalw Set.thy [INTER_def]
```
```   291     "(!!x. x:A ==> b: B(x)) ==> b : (INT x:A. B(x))";
```
```   292 by (REPEAT (ares_tac ([CollectI,ballI] @ prems) 1));
```
```   293 val INT_I = result();
```
```   294
```
```   295 val major::prems = goalw Set.thy [INTER_def]
```
```   296     "[| b : (INT x:A. B(x));  a:A |] ==> b: B(a)";
```
```   297 by (rtac (major RS CollectD RS bspec) 1);
```
```   298 by (resolve_tac prems 1);
```
```   299 val INT_D = result();
```
```   300
```
```   301 (*"Classical" elimination rule -- does not require proving X:C *)
```
```   302 val major::prems = goalw Set.thy [INTER_def]
```
```   303     "[| b : (INT x:A. B(x));  b: B(a) ==> R;  ~ a:A ==> R |] ==> R";
```
```   304 by (rtac (major RS CollectD RS ballE) 1);
```
```   305 by (REPEAT (eresolve_tac prems 1));
```
```   306 val INT_E = result();
```
```   307
```
```   308 val prems = goal Set.thy
```
```   309     "[| A=B;  !!x. x:B ==> C(x) = D(x) |] ==> \
```
```   310 \    (INT x:A. C(x)) = (INT x:B. D(x))";
```
```   311 by (REPEAT_FIRST (resolve_tac [INT_I,equalityI,subsetI]));
```
```   312 by (REPEAT (dtac INT_D 1
```
```   313      ORELSE ares_tac (prems RL [equalityD1,equalityD2] RL [subsetD]) 1));
```
```   314 val INT_cong = result();
```
```   315
```
```   316 (*** Rules for Unions ***)
```
```   317
```
```   318 (*The order of the premises presupposes that C is rigid; A may be flexible*)
```
```   319 val prems = goalw Set.thy [Union_def]
```
```   320     "[| X:C;  A:X |] ==> A : Union(C)";
```
```   321 by (REPEAT (resolve_tac (prems @ [UN_I]) 1));
```
```   322 val UnionI = result();
```
```   323
```
```   324 val major::prems = goalw Set.thy [Union_def]
```
```   325     "[| A : Union(C);  !!X.[| A:X;  X:C |] ==> R |] ==> R";
```
```   326 by (rtac (major RS UN_E) 1);
```
```   327 by (REPEAT (ares_tac prems 1));
```
```   328 val UnionE = result();
```
```   329
```
```   330 (*** Rules for Inter ***)
```
```   331
```
```   332 val prems = goalw Set.thy [Inter_def]
```
```   333     "[| !!X. X:C ==> A:X |] ==> A : Inter(C)";
```
```   334 by (REPEAT (ares_tac ([INT_I] @ prems) 1));
```
```   335 val InterI = result();
```
```   336
```
```   337 (*A "destruct" rule -- every X in C contains A as an element, but
```
```   338   A:X can hold when X:C does not!  This rule is analogous to "spec". *)
```
```   339 val major::prems = goalw Set.thy [Inter_def]
```
```   340     "[| A : Inter(C);  X:C |] ==> A:X";
```
```   341 by (rtac (major RS INT_D) 1);
```
```   342 by (resolve_tac prems 1);
```
```   343 val InterD = result();
```
```   344
```
```   345 (*"Classical" elimination rule -- does not require proving X:C *)
```
```   346 val major::prems = goalw Set.thy [Inter_def]
```
```   347     "[| A : Inter(C);  A:X ==> R;  ~ X:C ==> R |] ==> R";
```
```   348 by (rtac (major RS INT_E) 1);
```
```   349 by (REPEAT (eresolve_tac prems 1));
```
```   350 val InterE = result();
```