src/HOL/Decision_Procs/cooper_tac.ML
changeset 29823 0ab754d13ccd
parent 29788 1b80ebe713a4
child 29948 cdf12a1cb963
equal deleted inserted replaced
29822:c45845743f04 29823:0ab754d13ccd
       
     1 (*  Title:      HOL/Reflection/cooper_tac.ML
       
     2     Author:     Amine Chaieb, TU Muenchen
       
     3 *)
       
     4 
       
     5 structure Cooper_Tac =
       
     6 struct
       
     7 
       
     8 val trace = ref false;
       
     9 fun trace_msg s = if !trace then tracing s else ();
       
    10 
       
    11 val cooper_ss = @{simpset};
       
    12 
       
    13 val nT = HOLogic.natT;
       
    14 val binarith = @{thms normalize_bin_simps};
       
    15 val comp_arith = binarith @ simp_thms
       
    16 
       
    17 val zdvd_int = @{thm zdvd_int};
       
    18 val zdiff_int_split = @{thm zdiff_int_split};
       
    19 val all_nat = @{thm all_nat};
       
    20 val ex_nat = @{thm ex_nat};
       
    21 val number_of1 = @{thm number_of1};
       
    22 val number_of2 = @{thm number_of2};
       
    23 val split_zdiv = @{thm split_zdiv};
       
    24 val split_zmod = @{thm split_zmod};
       
    25 val mod_div_equality' = @{thm mod_div_equality'};
       
    26 val split_div' = @{thm split_div'};
       
    27 val Suc_plus1 = @{thm Suc_plus1};
       
    28 val imp_le_cong = @{thm imp_le_cong};
       
    29 val conj_le_cong = @{thm conj_le_cong};
       
    30 val nat_mod_add_eq = @{thm mod_add1_eq} RS sym;
       
    31 val nat_mod_add_left_eq = @{thm mod_add_left_eq} RS sym;
       
    32 val nat_mod_add_right_eq = @{thm mod_add_right_eq} RS sym;
       
    33 val int_mod_add_eq = @{thm zmod_zadd1_eq} RS sym;
       
    34 val int_mod_add_left_eq = @{thm zmod_zadd_left_eq} RS sym;
       
    35 val int_mod_add_right_eq = @{thm zmod_zadd_right_eq} RS sym;
       
    36 val nat_div_add_eq = @{thm div_add1_eq} RS sym;
       
    37 val int_div_add_eq = @{thm zdiv_zadd1_eq} RS sym;
       
    38 
       
    39 fun prepare_for_linz q fm = 
       
    40   let
       
    41     val ps = Logic.strip_params fm
       
    42     val hs = map HOLogic.dest_Trueprop (Logic.strip_assums_hyp fm)
       
    43     val c = HOLogic.dest_Trueprop (Logic.strip_assums_concl fm)
       
    44     fun mk_all ((s, T), (P,n)) =
       
    45       if 0 mem loose_bnos P then
       
    46         (HOLogic.all_const T $ Abs (s, T, P), n)
       
    47       else (incr_boundvars ~1 P, n-1)
       
    48     fun mk_all2 (v, t) = HOLogic.all_const (fastype_of v) $ lambda v t;
       
    49     val rhs = hs
       
    50     val np = length ps
       
    51     val (fm',np) =  foldr (fn ((x, T), (fm,n)) => mk_all ((x, T), (fm,n)))
       
    52       (foldr HOLogic.mk_imp c rhs, np) ps
       
    53     val (vs, _) = List.partition (fn t => q orelse (type_of t) = nT)
       
    54       (OldTerm.term_frees fm' @ OldTerm.term_vars fm');
       
    55     val fm2 = foldr mk_all2 fm' vs
       
    56   in (fm2, np + length vs, length rhs) end;
       
    57 
       
    58 (*Object quantifier to meta --*)
       
    59 fun spec_step n th = if (n=0) then th else (spec_step (n-1) th) RS spec ;
       
    60 
       
    61 (* object implication to meta---*)
       
    62 fun mp_step n th = if (n=0) then th else (mp_step (n-1) th) RS mp;
       
    63 
       
    64 
       
    65 fun linz_tac ctxt q i = ObjectLogic.atomize_prems_tac i THEN (fn st =>
       
    66   let
       
    67     val g = List.nth (prems_of st, i - 1)
       
    68     val thy = ProofContext.theory_of ctxt
       
    69     (* Transform the term*)
       
    70     val (t,np,nh) = prepare_for_linz q g
       
    71     (* Some simpsets for dealing with mod div abs and nat*)
       
    72     val mod_div_simpset = HOL_basic_ss 
       
    73 			addsimps [refl,nat_mod_add_eq, nat_mod_add_left_eq, 
       
    74 				  nat_mod_add_right_eq, int_mod_add_eq, 
       
    75 				  int_mod_add_right_eq, int_mod_add_left_eq,
       
    76 				  nat_div_add_eq, int_div_add_eq,
       
    77 				  @{thm mod_self}, @{thm "zmod_self"},
       
    78 				  @{thm mod_by_0}, @{thm div_by_0},
       
    79 				  @{thm "zdiv_zero"}, @{thm "zmod_zero"}, @{thm "div_0"}, @{thm "mod_0"},
       
    80 				  @{thm "zdiv_1"}, @{thm "zmod_1"}, @{thm "div_1"}, @{thm "mod_1"},
       
    81 				  Suc_plus1]
       
    82 			addsimps @{thms add_ac}
       
    83 			addsimprocs [cancel_div_mod_proc]
       
    84     val simpset0 = HOL_basic_ss
       
    85       addsimps [mod_div_equality', Suc_plus1]
       
    86       addsimps comp_arith
       
    87       addsplits [split_zdiv, split_zmod, split_div', @{thm "split_min"}, @{thm "split_max"}]
       
    88     (* Simp rules for changing (n::int) to int n *)
       
    89     val simpset1 = HOL_basic_ss
       
    90       addsimps [nat_number_of_def, zdvd_int] @ map (fn r => r RS sym)
       
    91         [@{thm int_int_eq}, @{thm zle_int}, @{thm zless_int}, @{thm zadd_int}, @{thm zmult_int}]
       
    92       addsplits [zdiff_int_split]
       
    93     (*simp rules for elimination of int n*)
       
    94 
       
    95     val simpset2 = HOL_basic_ss
       
    96       addsimps [@{thm nat_0_le}, @{thm all_nat}, @{thm ex_nat}, @{thm number_of1}, @{thm number_of2}, @{thm int_0}, @{thm int_1}]
       
    97       addcongs [@{thm conj_le_cong}, @{thm imp_le_cong}]
       
    98     (* simp rules for elimination of abs *)
       
    99     val simpset3 = HOL_basic_ss addsplits [@{thm abs_split}]
       
   100     val ct = cterm_of thy (HOLogic.mk_Trueprop t)
       
   101     (* Theorem for the nat --> int transformation *)
       
   102     val pre_thm = Seq.hd (EVERY
       
   103       [simp_tac mod_div_simpset 1, simp_tac simpset0 1,
       
   104        TRY (simp_tac simpset1 1), TRY (simp_tac simpset2 1),
       
   105        TRY (simp_tac simpset3 1), TRY (simp_tac cooper_ss 1)]
       
   106       (trivial ct))
       
   107     fun assm_tac i = REPEAT_DETERM_N nh (assume_tac i)
       
   108     (* The result of the quantifier elimination *)
       
   109     val (th, tac) = case (prop_of pre_thm) of
       
   110         Const ("==>", _) $ (Const ("Trueprop", _) $ t1) $ _ =>
       
   111     let val pth = linzqe_oracle (cterm_of thy (Pattern.eta_long [] t1))
       
   112     in 
       
   113           ((pth RS iffD2) RS pre_thm,
       
   114             assm_tac (i + 1) THEN (if q then I else TRY) (rtac TrueI i))
       
   115     end
       
   116       | _ => (pre_thm, assm_tac i)
       
   117   in (rtac (((mp_step nh) o (spec_step np)) th) i 
       
   118       THEN tac) st
       
   119   end handle Subscript => no_tac st);
       
   120 
       
   121 fun linz_args meth =
       
   122  let val parse_flag = 
       
   123          Args.$$$ "no_quantify" >> (K (K false));
       
   124  in
       
   125    Method.simple_args 
       
   126   (Scan.optional (Args.$$$ "(" |-- Scan.repeat1 parse_flag --| Args.$$$ ")") [] >>
       
   127     curry (Library.foldl op |>) true)
       
   128     (fn q => fn ctxt => meth ctxt q 1)
       
   129   end;
       
   130 
       
   131 fun linz_method ctxt q i = Method.METHOD (fn facts =>
       
   132   Method.insert_tac facts 1 THEN linz_tac ctxt q i);
       
   133 
       
   134 val setup =
       
   135   Method.add_method ("cooper",
       
   136      linz_args linz_method,
       
   137      "decision procedure for linear integer arithmetic");
       
   138 
       
   139 end