src/HOL/Tools/SMT/smt_utils.ML
author boehmes
Wed, 15 Dec 2010 08:39:24 +0100
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child 41126 e0bd443c0fdd
permissions -rw-r--r--
moved SMT classes and dictionary functions to SMT_Utils
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(*  Title:      HOL/Tools/SMT/smt_utils.ML
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    Author:     Sascha Boehme, TU Muenchen
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General utility functions.
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*)
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signature SMT_UTILS =
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sig
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  (*basic combinators*)
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  val repeat: ('a -> 'a option) -> 'a -> 'a
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  val repeat_yield: ('a -> 'b -> ('a * 'b) option) -> 'a -> 'b -> 'a * 'b
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  (*class dictionaries*)
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  type class = string list
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  val basicC: class
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  type 'a dict = (class * 'a) Ord_List.T
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  val dict_map_default: class * 'a -> ('a -> 'a) -> 'a dict -> 'a dict
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  val dict_update: class * 'a -> 'a dict -> 'a dict
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  val dict_merge: ('a * 'a -> 'a) -> 'a dict * 'a dict -> 'a dict
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  val dict_lookup: 'a dict -> class -> 'a list
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  (*types*)
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  val dest_funT: int -> typ -> typ list * typ
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  (*terms*)
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  val dest_conj: term -> term * term
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  val dest_disj: term -> term * term
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  (*patterns and instantiations*)
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  val mk_const_pat: theory -> string -> (ctyp -> 'a) -> 'a * cterm
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  val destT1: ctyp -> ctyp
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  val destT2: ctyp -> ctyp
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  val instTs: ctyp list -> ctyp list * cterm -> cterm
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  val instT: ctyp -> ctyp * cterm -> cterm
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  val instT': cterm -> ctyp * cterm -> cterm
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  (*certified terms*)
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  val certify: Proof.context -> term -> cterm
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  val typ_of: cterm -> typ
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  val dest_cabs: cterm -> Proof.context -> cterm * Proof.context
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  val dest_all_cabs: cterm -> Proof.context -> cterm * Proof.context
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  val dest_cbinder: cterm -> Proof.context -> cterm * Proof.context
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  val dest_all_cbinders: cterm -> Proof.context -> cterm * Proof.context
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  val mk_cprop: cterm -> cterm
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  val dest_cprop: cterm -> cterm
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  val mk_cequals: cterm -> cterm -> cterm
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  (*conversions*)
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  val if_conv: (term -> bool) -> conv -> conv -> conv
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  val if_true_conv: (term -> bool) -> conv -> conv
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  val binders_conv: (Proof.context -> conv) -> Proof.context -> conv
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  val prop_conv: conv -> conv
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end
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structure SMT_Utils: SMT_UTILS =
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struct
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(* basic combinators *)
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fun repeat f =
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  let fun rep x = (case f x of SOME y => rep y | NONE => x)
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  in rep end
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fun repeat_yield f =
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  let fun rep x y = (case f x y of SOME (x', y') => rep x' y' | NONE => (x, y))
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  in rep end
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(* class dictionaries *)
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type class = string list
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val basicC = []
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type 'a dict = (class * 'a) Ord_List.T
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fun class_ord ((cs1, _), (cs2, _)) = list_ord fast_string_ord (cs1, cs2)
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fun dict_insert (cs, x) d =
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  if AList.defined (op =) d cs then d
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  else Ord_List.insert class_ord (cs, x) d
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fun dict_map_default (cs, x) f =
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  dict_insert (cs, x) #> AList.map_entry (op =) cs f
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fun dict_update (e as (_, x)) = dict_map_default e (K x)
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fun dict_merge val_merge = sort class_ord o AList.join (op =) (K val_merge)
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fun dict_lookup d cs =
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  let fun match (cs', x) = if is_prefix (op =) cs' cs then SOME x else NONE
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  in map_filter match d end
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(* types *)
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val dest_funT =
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  let
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    fun dest Ts 0 T = (rev Ts, T)
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      | dest Ts i (Type ("fun", [T, U])) = dest (T::Ts) (i-1) U
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      | dest _ _ T = raise TYPE ("not a function type", [T], [])
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  in dest [] end
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(* terms *)
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fun dest_conj (@{const HOL.conj} $ t $ u) = (t, u)
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  | dest_conj t = raise TERM ("not a conjunction", [t])
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fun dest_disj (@{const HOL.disj} $ t $ u) = (t, u)
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  | dest_disj t = raise TERM ("not a disjunction", [t])
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(* patterns and instantiations *)
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fun mk_const_pat thy name destT =
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  let val cpat = Thm.cterm_of thy (Const (name, Sign.the_const_type thy name))
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  in (destT (Thm.ctyp_of_term cpat), cpat) end
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val destT1 = hd o Thm.dest_ctyp
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val destT2 = hd o tl o Thm.dest_ctyp
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fun instTs cUs (cTs, ct) = Thm.instantiate_cterm (cTs ~~ cUs, []) ct
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fun instT cU (cT, ct) = instTs [cU] ([cT], ct)
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fun instT' ct = instT (Thm.ctyp_of_term ct)
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(* certified terms *)
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fun certify ctxt = Thm.cterm_of (ProofContext.theory_of ctxt)
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fun typ_of ct = #T (Thm.rep_cterm ct) 
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fun dest_cabs ct ctxt =
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  (case Thm.term_of ct of
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    Abs _ =>
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      let val (n, ctxt') = yield_singleton Variable.variant_fixes Name.uu ctxt
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      in (snd (Thm.dest_abs (SOME n) ct), ctxt') end
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  | _ => raise CTERM ("no abstraction", [ct]))
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val dest_all_cabs = repeat_yield (try o dest_cabs) 
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fun dest_cbinder ct ctxt =
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  (case Thm.term_of ct of
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    Const _ $ Abs _ => dest_cabs (Thm.dest_arg ct) ctxt
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  | _ => raise CTERM ("not a binder", [ct]))
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val dest_all_cbinders = repeat_yield (try o dest_cbinder)
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val mk_cprop = Thm.capply (Thm.cterm_of @{theory} @{const Trueprop})
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fun dest_cprop ct =
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  (case Thm.term_of ct of
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    @{const Trueprop} $ _ => Thm.dest_arg ct
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  | _ => raise CTERM ("not a property", [ct]))
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val equals = mk_const_pat @{theory} @{const_name "=="} destT1
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fun mk_cequals ct cu = Thm.mk_binop (instT' ct equals) ct cu
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(* conversions *)
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fun if_conv pred cv1 cv2 ct = if pred (Thm.term_of ct) then cv1 ct else cv2 ct
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fun if_true_conv pred cv = if_conv pred cv Conv.all_conv
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fun binders_conv cv ctxt =
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  Conv.binder_conv (binders_conv cv o snd) ctxt else_conv cv ctxt
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fun prop_conv cv ct =
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  (case Thm.term_of ct of
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    @{const Trueprop} $ _ => Conv.arg_conv cv ct
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  | _ => raise CTERM ("not a property", [ct]))
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end