src/Pure/thm.ML
author wenzelm
Tue Jun 13 23:41:52 2006 +0200 (2006-06-13)
changeset 19881 47937afefdc9
parent 19861 620d90091788
child 19910 2b4a222fef3c
permissions -rw-r--r--
added hyps_of;
tuned;
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(*  Title:      Pure/thm.ML
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    ID:         $Id$
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    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1994  University of Cambridge
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The very core of Isabelle's Meta Logic: certified types and terms,
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meta theorems, meta rules (including lifting and resolution).
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*)
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signature BASIC_THM =
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  sig
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  (*certified types*)
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  type ctyp
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  val rep_ctyp: ctyp ->
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   {thy: theory,
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    sign: theory,       (*obsolete*)
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    T: typ,
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    sorts: sort list}
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  val theory_of_ctyp: ctyp -> theory
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  val typ_of: ctyp -> typ
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  val ctyp_of: theory -> typ -> ctyp
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  val read_ctyp: theory -> string -> ctyp
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  (*certified terms*)
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  type cterm
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  exception CTERM of string
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  val rep_cterm: cterm ->
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   {thy: theory,
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    sign: theory,       (*obsolete*)
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    t: term,
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    T: typ,
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    maxidx: int,
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    sorts: sort list}
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  val crep_cterm: cterm ->
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    {thy: theory, sign: theory, t: term, T: ctyp, maxidx: int, sorts: sort list}
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  val theory_of_cterm: cterm -> theory
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  val term_of: cterm -> term
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  val cterm_of: theory -> term -> cterm
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  val ctyp_of_term: cterm -> ctyp
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  val read_cterm: theory -> string * typ -> cterm
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  val adjust_maxidx: cterm -> cterm
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  val read_def_cterm:
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    theory * (indexname -> typ option) * (indexname -> sort option) ->
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    string list -> bool -> string * typ -> cterm * (indexname * typ) list
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  val read_def_cterms:
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    theory * (indexname -> typ option) * (indexname -> sort option) ->
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    string list -> bool -> (string * typ)list
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    -> cterm list * (indexname * typ)list
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  type tag              (* = string * string list *)
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  (*meta theorems*)
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  type thm
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  val rep_thm: thm ->
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   {thy: theory,
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    sign: theory,       (*obsolete*)
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    der: bool * Proofterm.proof,
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    maxidx: int,
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    shyps: sort list,
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    hyps: term list,
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    tpairs: (term * term) list,
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    prop: term}
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  val crep_thm: thm ->
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   {thy: theory,
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    sign: theory,       (*obsolete*)
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    der: bool * Proofterm.proof,
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    maxidx: int,
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    shyps: sort list,
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    hyps: cterm list,
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    tpairs: (cterm * cterm) list,
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    prop: cterm}
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  exception THM of string * int * thm list
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  type attribute     (* = Context.generic * thm -> Context.generic * thm *)
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  val eq_thm: thm * thm -> bool
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  val eq_thms: thm list * thm list -> bool
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  val theory_of_thm: thm -> theory
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  val sign_of_thm: thm -> theory    (*obsolete*)
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  val prop_of: thm -> term
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  val proof_of: thm -> Proofterm.proof
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  val tpairs_of: thm -> (term * term) list
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  val concl_of: thm -> term
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  val prems_of: thm -> term list
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  val nprems_of: thm -> int
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  val cprop_of: thm -> cterm
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  val cprem_of: thm -> int -> cterm
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  val transfer: theory -> thm -> thm
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  val weaken: cterm -> thm -> thm
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  val extra_shyps: thm -> sort list
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  val strip_shyps: thm -> thm
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  val get_axiom_i: theory -> string -> thm
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  val get_axiom: theory -> xstring -> thm
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  val def_name: string -> string
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  val get_def: theory -> xstring -> thm
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  val axioms_of: theory -> (string * thm) list
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  (*meta rules*)
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  val assume: cterm -> thm
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  val implies_intr: cterm -> thm -> thm
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  val implies_elim: thm -> thm -> thm
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  val forall_intr: cterm -> thm -> thm
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  val forall_elim: cterm -> thm -> thm
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  val reflexive: cterm -> thm
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  val symmetric: thm -> thm
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  val transitive: thm -> thm -> thm
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  val beta_conversion: bool -> cterm -> thm
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  val eta_conversion: cterm -> thm
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  val abstract_rule: string -> cterm -> thm -> thm
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  val combination: thm -> thm -> thm
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  val equal_intr: thm -> thm -> thm
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  val equal_elim: thm -> thm -> thm
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  val flexflex_rule: thm -> thm Seq.seq
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  val instantiate: (ctyp * ctyp) list * (cterm * cterm) list -> thm -> thm
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  val trivial: cterm -> thm
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  val class_triv: theory -> class -> thm
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  val unconstrainT: ctyp -> thm -> thm
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  val varifyT: thm -> thm
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  val varifyT': (string * sort) list -> thm -> ((string * sort) * indexname) list * thm
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  val dest_state: thm * int -> (term * term) list * term list * term * term
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  val lift_rule: cterm -> thm -> thm
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  val incr_indexes: int -> thm -> thm
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  val assumption: int -> thm -> thm Seq.seq
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  val eq_assumption: int -> thm -> thm
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  val rotate_rule: int -> int -> thm -> thm
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  val permute_prems: int -> int -> thm -> thm
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  val rename_params_rule: string list * int -> thm -> thm
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  val compose_no_flatten: bool -> thm * int -> int -> thm -> thm Seq.seq
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  val bicompose: bool -> bool * thm * int -> int -> thm -> thm Seq.seq
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  val biresolution: bool -> (bool * thm) list -> int -> thm -> thm Seq.seq
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  val invoke_oracle: theory -> xstring -> theory * Object.T -> thm
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  val invoke_oracle_i: theory -> string -> theory * Object.T -> thm
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end;
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signature THM =
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sig
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  include BASIC_THM
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  val dest_ctyp: ctyp -> ctyp list
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  val dest_comb: cterm -> cterm * cterm
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  val dest_abs: string option -> cterm -> cterm * cterm
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  val capply: cterm -> cterm -> cterm
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  val cabs: cterm -> cterm -> cterm
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  val major_prem_of: thm -> term
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  val no_prems: thm -> bool
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  val rule_attribute: (Context.generic -> thm -> thm) -> attribute
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  val declaration_attribute: (thm -> Context.generic -> Context.generic) -> attribute
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  val theory_attributes: attribute list -> theory * thm -> theory * thm
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  val proof_attributes: attribute list -> Context.proof * thm -> Context.proof * thm
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  val no_attributes: 'a -> 'a * 'b list
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  val simple_fact: 'a -> ('a * 'b list) list
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  val terms_of_tpairs: (term * term) list -> term list
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  val maxidx_of: thm -> int
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  val hyps_of: thm -> term list
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  val full_prop_of: thm -> term
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  val get_name_tags: thm -> string * tag list
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  val put_name_tags: string * tag list -> thm -> thm
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  val name_of_thm: thm -> string
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  val tags_of_thm: thm -> tag list
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  val name_thm: string * thm -> thm
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  val compress: thm -> thm
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  val adjust_maxidx_thm: thm -> thm
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  val rename_boundvars: term -> term -> thm -> thm
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  val cterm_match: cterm * cterm -> (ctyp * ctyp) list * (cterm * cterm) list
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  val cterm_first_order_match: cterm * cterm -> (ctyp * ctyp) list * (cterm * cterm) list
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  val cterm_incr_indexes: int -> cterm -> cterm
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  val freezeT: thm -> thm
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end;
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structure Thm: THM =
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struct
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(*** Certified terms and types ***)
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(** collect occurrences of sorts -- unless all sorts non-empty **)
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fun may_insert_typ_sorts thy T = if Sign.all_sorts_nonempty thy then I else Sorts.insert_typ T;
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fun may_insert_term_sorts thy t = if Sign.all_sorts_nonempty thy then I else Sorts.insert_term t;
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(*NB: type unification may invent new sorts*)
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fun may_insert_env_sorts thy (env as Envir.Envir {iTs, ...}) =
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  if Sign.all_sorts_nonempty thy then I
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  else Vartab.fold (fn (_, (_, T)) => Sorts.insert_typ T) iTs;
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(** certified types **)
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datatype ctyp = Ctyp of {thy_ref: theory_ref, T: typ, sorts: sort list};
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fun rep_ctyp (Ctyp {thy_ref, T, sorts}) =
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  let val thy = Theory.deref thy_ref
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  in {thy = thy, sign = thy, T = T, sorts = sorts} end;
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fun theory_of_ctyp (Ctyp {thy_ref, ...}) = Theory.deref thy_ref;
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fun typ_of (Ctyp {T, ...}) = T;
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fun ctyp_of thy raw_T =
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  let val T = Sign.certify_typ thy raw_T
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  in Ctyp {thy_ref = Theory.self_ref thy, T = T, sorts = may_insert_typ_sorts thy T []} end;
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fun read_ctyp thy s =
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  let val T = Sign.read_typ (thy, K NONE) s
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  in Ctyp {thy_ref = Theory.self_ref thy, T = T, sorts = may_insert_typ_sorts thy T []} end;
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fun dest_ctyp (Ctyp {thy_ref, T = Type (s, Ts), sorts}) =
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      map (fn T => Ctyp {thy_ref = thy_ref, T = T, sorts = sorts}) Ts
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  | dest_ctyp cT = raise TYPE ("dest_ctyp", [typ_of cT], []);
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(** certified terms **)
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(*certified terms with checked typ, maxidx, and sorts*)
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datatype cterm = Cterm of
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 {thy_ref: theory_ref,
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  t: term,
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  T: typ,
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  maxidx: int,
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  sorts: sort list};
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exception CTERM of string;
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fun rep_cterm (Cterm {thy_ref, t, T, maxidx, sorts}) =
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  let val thy =  Theory.deref thy_ref
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  in {thy = thy, sign = thy, t = t, T = T, maxidx = maxidx, sorts = sorts} end;
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fun crep_cterm (Cterm {thy_ref, t, T, maxidx, sorts}) =
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  let val thy = Theory.deref thy_ref in
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   {thy = thy, sign = thy, t = t, T = Ctyp {thy_ref = thy_ref, T = T, sorts = sorts},
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    maxidx = maxidx, sorts = sorts}
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  end;
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fun theory_of_cterm (Cterm {thy_ref, ...}) = Theory.deref thy_ref;
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fun term_of (Cterm {t, ...}) = t;
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fun ctyp_of_term (Cterm {thy_ref, T, sorts, ...}) =
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  Ctyp {thy_ref = thy_ref, T = T, sorts = sorts};
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fun cterm_of thy tm =
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  let
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    val (t, T, maxidx) = Sign.certify_term thy tm;
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    val sorts = may_insert_term_sorts thy t [];
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  in Cterm {thy_ref = Theory.self_ref thy, t = t, T = T, maxidx = maxidx, sorts = sorts} end;
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fun merge_thys0 (Cterm {thy_ref = r1, ...}) (Cterm {thy_ref = r2, ...}) =
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  Theory.merge_refs (r1, r2);
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(*Destruct application in cterms*)
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fun dest_comb (Cterm {t = t $ u, T, thy_ref, maxidx, sorts}) =
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      let val A = Term.argument_type_of t in
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        (Cterm {t = t, T = A --> T, thy_ref = thy_ref, maxidx = maxidx, sorts = sorts},
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         Cterm {t = u, T = A, thy_ref = thy_ref, maxidx = maxidx, sorts = sorts})
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      end
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  | dest_comb _ = raise CTERM "dest_comb";
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(*Destruct abstraction in cterms*)
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fun dest_abs a (Cterm {t = Abs (x, T, t), T = Type ("fun", [_, U]), thy_ref, maxidx, sorts}) =
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      let val (y', t') = Term.dest_abs (the_default x a, T, t) in
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        (Cterm {t = Free (y', T), T = T, thy_ref = thy_ref, maxidx = maxidx, sorts = sorts},
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          Cterm {t = t', T = U, thy_ref = thy_ref, maxidx = maxidx, sorts = sorts})
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      end
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  | dest_abs _ _ = raise CTERM "dest_abs";
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(*Makes maxidx precise: it is often too big*)
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fun adjust_maxidx (ct as Cterm {thy_ref, t, T, maxidx, sorts}) =
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  if maxidx = ~1 then ct
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  else Cterm {thy_ref = thy_ref, t = t, T = T, maxidx = maxidx_of_term t, sorts = sorts};
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(*Form cterm out of a function and an argument*)
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fun capply
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  (cf as Cterm {t = f, T = Type ("fun", [dty, rty]), maxidx = maxidx1, sorts = sorts1, ...})
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  (cx as Cterm {t = x, T, maxidx = maxidx2, sorts = sorts2, ...}) =
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    if T = dty then
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      Cterm {thy_ref = merge_thys0 cf cx,
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        t = f $ x,
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        T = rty,
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        maxidx = Int.max (maxidx1, maxidx2),
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        sorts = Sorts.union sorts1 sorts2}
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      else raise CTERM "capply: types don't agree"
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  | capply _ _ = raise CTERM "capply: first arg is not a function"
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fun cabs
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  (ct1 as Cterm {t = t1, T = T1, maxidx = maxidx1, sorts = sorts1, ...})
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  (ct2 as Cterm {t = t2, T = T2, maxidx = maxidx2, sorts = sorts2, ...}) =
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    let val t = lambda t1 t2 handle TERM _ => raise CTERM "cabs: malformed first argument" in
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      Cterm {thy_ref = merge_thys0 ct1 ct2,
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        t = t, T = T1 --> T2,
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        maxidx = Int.max (maxidx1, maxidx2),
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        sorts = Sorts.union sorts1 sorts2}
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    end;
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(*Matching of cterms*)
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fun gen_cterm_match match
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    (ct1 as Cterm {t = t1, maxidx = maxidx1, sorts = sorts1, ...},
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     ct2 as Cterm {t = t2, maxidx = maxidx2, sorts = sorts2, ...}) =
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  let
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    val thy_ref = merge_thys0 ct1 ct2;
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    val (Tinsts, tinsts) = match (Theory.deref thy_ref) (t1, t2) (Vartab.empty, Vartab.empty);
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    val maxidx = Int.max (maxidx1, maxidx2);
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    val sorts = Sorts.union sorts1 sorts2;
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    fun mk_cTinst (ixn, (S, T)) =
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      (Ctyp {T = TVar (ixn, S), thy_ref = thy_ref, sorts = sorts},
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       Ctyp {T = T, thy_ref = thy_ref, sorts = sorts});
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    fun mk_ctinst (ixn, (T, t)) =
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      let val T = Envir.typ_subst_TVars Tinsts T in
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   306
        (Cterm {t = Var (ixn, T), T = T, thy_ref = thy_ref, maxidx = maxidx, sorts = sorts},
wenzelm@16656
   307
         Cterm {t = t, T = T, thy_ref = thy_ref, maxidx = maxidx, sorts = sorts})
berghofe@10416
   308
      end;
wenzelm@16656
   309
  in (Vartab.fold (cons o mk_cTinst) Tinsts [], Vartab.fold (cons o mk_ctinst) tinsts []) end;
berghofe@10416
   310
berghofe@10416
   311
val cterm_match = gen_cterm_match Pattern.match;
berghofe@10416
   312
val cterm_first_order_match = gen_cterm_match Pattern.first_order_match;
berghofe@10416
   313
berghofe@10416
   314
(*Incrementing indexes*)
wenzelm@16601
   315
fun cterm_incr_indexes i (ct as Cterm {thy_ref, t, T, maxidx, sorts}) =
wenzelm@16601
   316
  if i < 0 then raise CTERM "negative increment"
wenzelm@16601
   317
  else if i = 0 then ct
wenzelm@16601
   318
  else Cterm {thy_ref = thy_ref, t = Logic.incr_indexes ([], i) t,
wenzelm@16884
   319
    T = Logic.incr_tvar i T, maxidx = maxidx + i, sorts = sorts};
berghofe@10416
   320
wenzelm@2509
   321
wenzelm@2509
   322
wenzelm@574
   323
(** read cterms **)   (*exception ERROR*)
wenzelm@250
   324
nipkow@4281
   325
(*read terms, infer types, certify terms*)
wenzelm@16425
   326
fun read_def_cterms (thy, types, sorts) used freeze sTs =
wenzelm@250
   327
  let
wenzelm@16425
   328
    val (ts', tye) = Sign.read_def_terms (thy, types, sorts) used freeze sTs;
wenzelm@16425
   329
    val cts = map (cterm_of thy) ts'
wenzelm@2979
   330
      handle TYPE (msg, _, _) => error msg
wenzelm@2386
   331
           | TERM (msg, _) => error msg;
nipkow@4281
   332
  in (cts, tye) end;
nipkow@4281
   333
nipkow@4281
   334
(*read term, infer types, certify term*)
nipkow@4281
   335
fun read_def_cterm args used freeze aT =
nipkow@4281
   336
  let val ([ct],tye) = read_def_cterms args used freeze [aT]
nipkow@4281
   337
  in (ct,tye) end;
lcp@229
   338
wenzelm@16425
   339
fun read_cterm thy = #1 o read_def_cterm (thy, K NONE, K NONE) [] true;
lcp@229
   340
wenzelm@250
   341
wenzelm@6089
   342
(*tags provide additional comment, apart from the axiom/theorem name*)
wenzelm@6089
   343
type tag = string * string list;
wenzelm@6089
   344
wenzelm@2509
   345
wenzelm@387
   346
(*** Meta theorems ***)
lcp@229
   347
berghofe@11518
   348
structure Pt = Proofterm;
berghofe@11518
   349
clasohm@0
   350
datatype thm = Thm of
wenzelm@16425
   351
 {thy_ref: theory_ref,         (*dynamic reference to theory*)
berghofe@11518
   352
  der: bool * Pt.proof,        (*derivation*)
wenzelm@3967
   353
  maxidx: int,                 (*maximum index of any Var or TVar*)
wenzelm@16601
   354
  shyps: sort list,            (*sort hypotheses as ordered list*)
wenzelm@16601
   355
  hyps: term list,             (*hypotheses as ordered list*)
berghofe@13658
   356
  tpairs: (term * term) list,  (*flex-flex pairs*)
wenzelm@3967
   357
  prop: term};                 (*conclusion*)
clasohm@0
   358
wenzelm@16725
   359
(*errors involving theorems*)
wenzelm@16725
   360
exception THM of string * int * thm list;
berghofe@13658
   361
wenzelm@16425
   362
fun rep_thm (Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@16425
   363
  let val thy = Theory.deref thy_ref in
wenzelm@16425
   364
   {thy = thy, sign = thy, der = der, maxidx = maxidx,
wenzelm@16425
   365
    shyps = shyps, hyps = hyps, tpairs = tpairs, prop = prop}
wenzelm@16425
   366
  end;
clasohm@0
   367
wenzelm@16425
   368
(*version of rep_thm returning cterms instead of terms*)
wenzelm@16425
   369
fun crep_thm (Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@16425
   370
  let
wenzelm@16425
   371
    val thy = Theory.deref thy_ref;
wenzelm@16601
   372
    fun cterm max t = Cterm {thy_ref = thy_ref, t = t, T = propT, maxidx = max, sorts = shyps};
wenzelm@16425
   373
  in
wenzelm@16425
   374
   {thy = thy, sign = thy, der = der, maxidx = maxidx, shyps = shyps,
wenzelm@16425
   375
    hyps = map (cterm ~1) hyps,
wenzelm@16425
   376
    tpairs = map (pairself (cterm maxidx)) tpairs,
wenzelm@16425
   377
    prop = cterm maxidx prop}
clasohm@1517
   378
  end;
clasohm@1517
   379
wenzelm@16725
   380
fun terms_of_tpairs tpairs = fold_rev (fn (t, u) => cons t o cons u) tpairs [];
wenzelm@16725
   381
wenzelm@16725
   382
fun eq_tpairs ((t, u), (t', u')) = t aconv t' andalso u aconv u';
wenzelm@18944
   383
fun union_tpairs ts us = Library.merge eq_tpairs (ts, us);
wenzelm@16884
   384
val maxidx_tpairs = fold (fn (t, u) => Term.maxidx_term t #> Term.maxidx_term u);
wenzelm@16725
   385
wenzelm@16725
   386
fun attach_tpairs tpairs prop =
wenzelm@16725
   387
  Logic.list_implies (map Logic.mk_equals tpairs, prop);
wenzelm@16725
   388
wenzelm@16725
   389
fun full_prop_of (Thm {tpairs, prop, ...}) = attach_tpairs tpairs prop;
wenzelm@16945
   390
wenzelm@16945
   391
wenzelm@16945
   392
(* merge theories of cterms/thms; raise exception if incompatible *)
wenzelm@16945
   393
wenzelm@16945
   394
fun merge_thys1 (Cterm {thy_ref = r1, ...}) (th as Thm {thy_ref = r2, ...}) =
wenzelm@16945
   395
  Theory.merge_refs (r1, r2) handle TERM (msg, _) => raise THM (msg, 0, [th]);
wenzelm@16945
   396
wenzelm@16945
   397
fun merge_thys2 (th1 as Thm {thy_ref = r1, ...}) (th2 as Thm {thy_ref = r2, ...}) =
wenzelm@16945
   398
  Theory.merge_refs (r1, r2) handle TERM (msg, _) => raise THM (msg, 0, [th1, th2]);
wenzelm@16945
   399
clasohm@0
   400
wenzelm@16425
   401
(*attributes subsume any kind of rules or context modifiers*)
wenzelm@18733
   402
type attribute = Context.generic * thm -> Context.generic * thm;
wenzelm@18733
   403
wenzelm@18733
   404
fun rule_attribute f (x, th) = (x, f x th);
wenzelm@18733
   405
fun declaration_attribute f (x, th) = (f th x, th);
wenzelm@18733
   406
wenzelm@18733
   407
fun apply_attributes mk dest =
wenzelm@18733
   408
  let
wenzelm@18733
   409
    fun app [] = I
wenzelm@18733
   410
      | app ((f: attribute) :: fs) = fn (x, th) => f (mk x, th) |>> dest |> app fs;
wenzelm@18733
   411
  in app end;
wenzelm@18733
   412
wenzelm@18733
   413
val theory_attributes = apply_attributes Context.Theory Context.the_theory;
wenzelm@18733
   414
val proof_attributes = apply_attributes Context.Proof Context.the_proof;
wenzelm@17708
   415
wenzelm@6089
   416
fun no_attributes x = (x, []);
wenzelm@17345
   417
fun simple_fact x = [(x, [])];
wenzelm@6089
   418
wenzelm@16601
   419
wenzelm@16656
   420
(* hyps *)
wenzelm@16601
   421
wenzelm@16945
   422
val insert_hyps = OrdList.insert Term.fast_term_ord;
wenzelm@16679
   423
val remove_hyps = OrdList.remove Term.fast_term_ord;
wenzelm@16679
   424
val union_hyps = OrdList.union Term.fast_term_ord;
wenzelm@16679
   425
val eq_set_hyps = OrdList.eq_set Term.fast_term_ord;
wenzelm@16601
   426
wenzelm@16601
   427
wenzelm@16601
   428
(* eq_thm(s) *)
wenzelm@16601
   429
wenzelm@3994
   430
fun eq_thm (th1, th2) =
wenzelm@3994
   431
  let
wenzelm@16425
   432
    val {thy = thy1, shyps = shyps1, hyps = hyps1, tpairs = tpairs1, prop = prop1, ...} =
wenzelm@9031
   433
      rep_thm th1;
wenzelm@16425
   434
    val {thy = thy2, shyps = shyps2, hyps = hyps2, tpairs = tpairs2, prop = prop2, ...} =
wenzelm@9031
   435
      rep_thm th2;
wenzelm@3994
   436
  in
wenzelm@16601
   437
    Context.joinable (thy1, thy2) andalso
wenzelm@16601
   438
    Sorts.eq_set (shyps1, shyps2) andalso
wenzelm@16601
   439
    eq_set_hyps (hyps1, hyps2) andalso
wenzelm@16656
   440
    equal_lists eq_tpairs (tpairs1, tpairs2) andalso
wenzelm@3994
   441
    prop1 aconv prop2
wenzelm@3994
   442
  end;
wenzelm@387
   443
wenzelm@16135
   444
val eq_thms = Library.equal_lists eq_thm;
wenzelm@16135
   445
wenzelm@16425
   446
fun theory_of_thm (Thm {thy_ref, ...}) = Theory.deref thy_ref;
wenzelm@16425
   447
val sign_of_thm = theory_of_thm;
wenzelm@16425
   448
wenzelm@19429
   449
fun maxidx_of (Thm {maxidx, ...}) = maxidx;
wenzelm@19881
   450
fun hyps_of (Thm {hyps, ...}) = hyps;
wenzelm@12803
   451
fun prop_of (Thm {prop, ...}) = prop;
wenzelm@13528
   452
fun proof_of (Thm {der = (_, proof), ...}) = proof;
wenzelm@16601
   453
fun tpairs_of (Thm {tpairs, ...}) = tpairs;
clasohm@0
   454
wenzelm@16601
   455
val concl_of = Logic.strip_imp_concl o prop_of;
wenzelm@16601
   456
val prems_of = Logic.strip_imp_prems o prop_of;
wenzelm@16601
   457
fun nprems_of th = Logic.count_prems (prop_of th, 0);
wenzelm@19305
   458
fun no_prems th = nprems_of th = 0;
wenzelm@16601
   459
wenzelm@16601
   460
fun major_prem_of th =
wenzelm@16601
   461
  (case prems_of th of
wenzelm@16601
   462
    prem :: _ => Logic.strip_assums_concl prem
wenzelm@16601
   463
  | [] => raise THM ("major_prem_of: rule with no premises", 0, [th]));
wenzelm@16601
   464
wenzelm@16601
   465
(*the statement of any thm is a cterm*)
wenzelm@16601
   466
fun cprop_of (Thm {thy_ref, maxidx, shyps, prop, ...}) =
wenzelm@16601
   467
  Cterm {thy_ref = thy_ref, maxidx = maxidx, T = propT, t = prop, sorts = shyps};
wenzelm@16601
   468
wenzelm@18145
   469
fun cprem_of (th as Thm {thy_ref, maxidx, shyps, prop, ...}) i =
wenzelm@18035
   470
  Cterm {thy_ref = thy_ref, maxidx = maxidx, T = propT, sorts = shyps,
wenzelm@18145
   471
    t = Logic.nth_prem (i, prop) handle TERM _ => raise THM ("cprem_of", i, [th])};
wenzelm@18035
   472
wenzelm@16656
   473
(*explicit transfer to a super theory*)
wenzelm@16425
   474
fun transfer thy' thm =
wenzelm@3895
   475
  let
wenzelm@16425
   476
    val Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop} = thm;
wenzelm@16425
   477
    val thy = Theory.deref thy_ref;
wenzelm@3895
   478
  in
wenzelm@16945
   479
    if not (subthy (thy, thy')) then
wenzelm@16945
   480
      raise THM ("transfer: not a super theory", 0, [thm])
wenzelm@16945
   481
    else if eq_thy (thy, thy') then thm
wenzelm@16945
   482
    else
wenzelm@16945
   483
      Thm {thy_ref = Theory.self_ref thy',
wenzelm@16945
   484
        der = der,
wenzelm@16945
   485
        maxidx = maxidx,
wenzelm@16945
   486
        shyps = shyps,
wenzelm@16945
   487
        hyps = hyps,
wenzelm@16945
   488
        tpairs = tpairs,
wenzelm@16945
   489
        prop = prop}
wenzelm@3895
   490
  end;
wenzelm@387
   491
wenzelm@16945
   492
(*explicit weakening: maps |- B to A |- B*)
wenzelm@16945
   493
fun weaken raw_ct th =
wenzelm@16945
   494
  let
wenzelm@16945
   495
    val ct as Cterm {t = A, T, sorts, maxidx = maxidxA, ...} = adjust_maxidx raw_ct;
wenzelm@16945
   496
    val Thm {der, maxidx, shyps, hyps, tpairs, prop, ...} = th;
wenzelm@16945
   497
  in
wenzelm@16945
   498
    if T <> propT then
wenzelm@16945
   499
      raise THM ("weaken: assumptions must have type prop", 0, [])
wenzelm@16945
   500
    else if maxidxA <> ~1 then
wenzelm@16945
   501
      raise THM ("weaken: assumptions may not contain schematic variables", maxidxA, [])
wenzelm@16945
   502
    else
wenzelm@16945
   503
      Thm {thy_ref = merge_thys1 ct th,
wenzelm@16945
   504
        der = der,
wenzelm@16945
   505
        maxidx = maxidx,
wenzelm@16945
   506
        shyps = Sorts.union sorts shyps,
wenzelm@16945
   507
        hyps = insert_hyps A hyps,
wenzelm@16945
   508
        tpairs = tpairs,
wenzelm@16945
   509
        prop = prop}
wenzelm@16945
   510
  end;
wenzelm@16656
   511
wenzelm@16656
   512
clasohm@0
   513
wenzelm@1238
   514
(** sort contexts of theorems **)
wenzelm@1238
   515
wenzelm@16656
   516
fun present_sorts (Thm {hyps, tpairs, prop, ...}) =
wenzelm@16656
   517
  fold (fn (t, u) => Sorts.insert_term t o Sorts.insert_term u) tpairs
wenzelm@16656
   518
    (Sorts.insert_terms hyps (Sorts.insert_term prop []));
wenzelm@1238
   519
wenzelm@7642
   520
(*remove extra sorts that are non-empty by virtue of type signature information*)
wenzelm@7642
   521
fun strip_shyps (thm as Thm {shyps = [], ...}) = thm
wenzelm@16425
   522
  | strip_shyps (thm as Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@7642
   523
      let
wenzelm@16425
   524
        val thy = Theory.deref thy_ref;
wenzelm@16656
   525
        val shyps' =
wenzelm@16656
   526
          if Sign.all_sorts_nonempty thy then []
wenzelm@16656
   527
          else
wenzelm@16656
   528
            let
wenzelm@16656
   529
              val present = present_sorts thm;
wenzelm@16656
   530
              val extra = Sorts.subtract present shyps;
wenzelm@16656
   531
              val witnessed = map #2 (Sign.witness_sorts thy present extra);
wenzelm@16656
   532
            in Sorts.subtract witnessed shyps end;
wenzelm@7642
   533
      in
wenzelm@16425
   534
        Thm {thy_ref = thy_ref, der = der, maxidx = maxidx,
wenzelm@16656
   535
          shyps = shyps', hyps = hyps, tpairs = tpairs, prop = prop}
wenzelm@7642
   536
      end;
wenzelm@1238
   537
wenzelm@16656
   538
(*dangling sort constraints of a thm*)
wenzelm@16656
   539
fun extra_shyps (th as Thm {shyps, ...}) = Sorts.subtract (present_sorts th) shyps;
wenzelm@16656
   540
wenzelm@1238
   541
wenzelm@1238
   542
paulson@1529
   543
(** Axioms **)
wenzelm@387
   544
wenzelm@16425
   545
(*look up the named axiom in the theory or its ancestors*)
wenzelm@15672
   546
fun get_axiom_i theory name =
wenzelm@387
   547
  let
wenzelm@16425
   548
    fun get_ax thy =
wenzelm@17412
   549
      Symtab.lookup (#2 (#axioms (Theory.rep_theory thy))) name
wenzelm@16601
   550
      |> Option.map (fn prop =>
wenzelm@16601
   551
          Thm {thy_ref = Theory.self_ref thy,
wenzelm@16601
   552
            der = Pt.infer_derivs' I (false, Pt.axm_proof name prop),
wenzelm@16601
   553
            maxidx = maxidx_of_term prop,
wenzelm@16656
   554
            shyps = may_insert_term_sorts thy prop [],
wenzelm@16601
   555
            hyps = [],
wenzelm@16601
   556
            tpairs = [],
wenzelm@16601
   557
            prop = prop});
wenzelm@387
   558
  in
wenzelm@16425
   559
    (case get_first get_ax (theory :: Theory.ancestors_of theory) of
skalberg@15531
   560
      SOME thm => thm
skalberg@15531
   561
    | NONE => raise THEORY ("No axiom " ^ quote name, [theory]))
wenzelm@387
   562
  end;
wenzelm@387
   563
wenzelm@16352
   564
fun get_axiom thy =
wenzelm@16425
   565
  get_axiom_i thy o NameSpace.intern (Theory.axiom_space thy);
wenzelm@15672
   566
wenzelm@6368
   567
fun def_name name = name ^ "_def";
wenzelm@6368
   568
fun get_def thy = get_axiom thy o def_name;
wenzelm@4847
   569
paulson@1529
   570
wenzelm@776
   571
(*return additional axioms of this theory node*)
wenzelm@776
   572
fun axioms_of thy =
wenzelm@776
   573
  map (fn (s, _) => (s, get_axiom thy s))
wenzelm@16352
   574
    (Symtab.dest (#2 (#axioms (Theory.rep_theory thy))));
wenzelm@776
   575
wenzelm@6089
   576
wenzelm@6089
   577
(* name and tags -- make proof objects more readable *)
wenzelm@6089
   578
wenzelm@12923
   579
fun get_name_tags (Thm {hyps, prop, der = (_, prf), ...}) =
wenzelm@12923
   580
  Pt.get_name_tags hyps prop prf;
wenzelm@4018
   581
wenzelm@16425
   582
fun put_name_tags x (Thm {thy_ref, der = (ora, prf), maxidx,
wenzelm@16425
   583
      shyps, hyps, tpairs = [], prop}) = Thm {thy_ref = thy_ref,
wenzelm@16425
   584
        der = (ora, Pt.thm_proof (Theory.deref thy_ref) x hyps prop prf),
berghofe@13658
   585
        maxidx = maxidx, shyps = shyps, hyps = hyps, tpairs = [], prop = prop}
berghofe@13658
   586
  | put_name_tags _ thm =
berghofe@13658
   587
      raise THM ("put_name_tags: unsolved flex-flex constraints", 0, [thm]);
wenzelm@6089
   588
wenzelm@6089
   589
val name_of_thm = #1 o get_name_tags;
wenzelm@6089
   590
val tags_of_thm = #2 o get_name_tags;
wenzelm@6089
   591
wenzelm@6089
   592
fun name_thm (name, thm) = put_name_tags (name, tags_of_thm thm) thm;
clasohm@0
   593
clasohm@0
   594
paulson@1529
   595
(*Compression of theorems -- a separate rule, not integrated with the others,
paulson@1529
   596
  as it could be slow.*)
wenzelm@16425
   597
fun compress (Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@16991
   598
  let val thy = Theory.deref thy_ref in
wenzelm@16991
   599
    Thm {thy_ref = thy_ref,
wenzelm@16991
   600
      der = der,
wenzelm@16991
   601
      maxidx = maxidx,
wenzelm@16991
   602
      shyps = shyps,
wenzelm@16991
   603
      hyps = map (Compress.term thy) hyps,
wenzelm@16991
   604
      tpairs = map (pairself (Compress.term thy)) tpairs,
wenzelm@16991
   605
      prop = Compress.term thy prop}
wenzelm@16991
   606
  end;
wenzelm@16945
   607
wenzelm@16945
   608
fun adjust_maxidx_thm (Thm {thy_ref, der, shyps, hyps, tpairs, prop, ...}) =
wenzelm@16945
   609
  Thm {thy_ref = thy_ref,
wenzelm@16945
   610
    der = der,
wenzelm@16945
   611
    maxidx = maxidx_tpairs tpairs (maxidx_of_term prop),
wenzelm@16945
   612
    shyps = shyps,
wenzelm@16945
   613
    hyps = hyps,
wenzelm@16945
   614
    tpairs = tpairs,
wenzelm@16945
   615
    prop = prop};
wenzelm@564
   616
wenzelm@387
   617
wenzelm@2509
   618
paulson@1529
   619
(*** Meta rules ***)
clasohm@0
   620
wenzelm@16601
   621
(** primitive rules **)
clasohm@0
   622
wenzelm@16656
   623
(*The assumption rule A |- A*)
wenzelm@16601
   624
fun assume raw_ct =
wenzelm@16601
   625
  let val Cterm {thy_ref, t = prop, T, maxidx, sorts} = adjust_maxidx raw_ct in
wenzelm@16601
   626
    if T <> propT then
mengj@19230
   627
      raise THM ("assume: prop", 0, [])
wenzelm@16601
   628
    else if maxidx <> ~1 then
mengj@19230
   629
      raise THM ("assume: variables", maxidx, [])
wenzelm@16601
   630
    else Thm {thy_ref = thy_ref,
wenzelm@16601
   631
      der = Pt.infer_derivs' I (false, Pt.Hyp prop),
wenzelm@16601
   632
      maxidx = ~1,
wenzelm@16601
   633
      shyps = sorts,
wenzelm@16601
   634
      hyps = [prop],
wenzelm@16601
   635
      tpairs = [],
wenzelm@16601
   636
      prop = prop}
clasohm@0
   637
  end;
clasohm@0
   638
wenzelm@1220
   639
(*Implication introduction
wenzelm@3529
   640
    [A]
wenzelm@3529
   641
     :
wenzelm@3529
   642
     B
wenzelm@1220
   643
  -------
wenzelm@1220
   644
  A ==> B
wenzelm@1220
   645
*)
wenzelm@16601
   646
fun implies_intr
wenzelm@16679
   647
    (ct as Cterm {t = A, T, maxidx = maxidxA, sorts, ...})
wenzelm@16679
   648
    (th as Thm {der, maxidx, hyps, shyps, tpairs, prop, ...}) =
wenzelm@16601
   649
  if T <> propT then
wenzelm@16601
   650
    raise THM ("implies_intr: assumptions must have type prop", 0, [th])
wenzelm@16601
   651
  else
wenzelm@16601
   652
    Thm {thy_ref = merge_thys1 ct th,
wenzelm@16601
   653
      der = Pt.infer_derivs' (Pt.implies_intr_proof A) der,
wenzelm@16601
   654
      maxidx = Int.max (maxidxA, maxidx),
wenzelm@16601
   655
      shyps = Sorts.union sorts shyps,
wenzelm@16601
   656
      hyps = remove_hyps A hyps,
wenzelm@16601
   657
      tpairs = tpairs,
wenzelm@16601
   658
      prop = implies $ A $ prop};
clasohm@0
   659
paulson@1529
   660
wenzelm@1220
   661
(*Implication elimination
wenzelm@1220
   662
  A ==> B    A
wenzelm@1220
   663
  ------------
wenzelm@1220
   664
        B
wenzelm@1220
   665
*)
wenzelm@16601
   666
fun implies_elim thAB thA =
wenzelm@16601
   667
  let
wenzelm@16601
   668
    val Thm {maxidx = maxA, der = derA, hyps = hypsA, shyps = shypsA, tpairs = tpairsA,
wenzelm@16601
   669
      prop = propA, ...} = thA
wenzelm@16601
   670
    and Thm {der, maxidx, hyps, shyps, tpairs, prop, ...} = thAB;
wenzelm@16601
   671
    fun err () = raise THM ("implies_elim: major premise", 0, [thAB, thA]);
wenzelm@16601
   672
  in
wenzelm@16601
   673
    case prop of
wenzelm@16601
   674
      imp $ A $ B =>
wenzelm@16601
   675
        if imp = Term.implies andalso A aconv propA then
wenzelm@16656
   676
          Thm {thy_ref = merge_thys2 thAB thA,
wenzelm@16601
   677
            der = Pt.infer_derivs (curry Pt.%%) der derA,
wenzelm@16601
   678
            maxidx = Int.max (maxA, maxidx),
wenzelm@16601
   679
            shyps = Sorts.union shypsA shyps,
wenzelm@16601
   680
            hyps = union_hyps hypsA hyps,
wenzelm@16601
   681
            tpairs = union_tpairs tpairsA tpairs,
wenzelm@16601
   682
            prop = B}
wenzelm@16601
   683
        else err ()
wenzelm@16601
   684
    | _ => err ()
wenzelm@16601
   685
  end;
wenzelm@250
   686
wenzelm@1220
   687
(*Forall introduction.  The Free or Var x must not be free in the hypotheses.
wenzelm@16656
   688
    [x]
wenzelm@16656
   689
     :
wenzelm@16656
   690
     A
wenzelm@16656
   691
  ------
wenzelm@16656
   692
  !!x. A
wenzelm@1220
   693
*)
wenzelm@16601
   694
fun forall_intr
wenzelm@16601
   695
    (ct as Cterm {t = x, T, sorts, ...})
wenzelm@16679
   696
    (th as Thm {der, maxidx, shyps, hyps, tpairs, prop, ...}) =
wenzelm@16601
   697
  let
wenzelm@16601
   698
    fun result a =
wenzelm@16601
   699
      Thm {thy_ref = merge_thys1 ct th,
wenzelm@16601
   700
        der = Pt.infer_derivs' (Pt.forall_intr_proof x a) der,
wenzelm@16601
   701
        maxidx = maxidx,
wenzelm@16601
   702
        shyps = Sorts.union sorts shyps,
wenzelm@16601
   703
        hyps = hyps,
wenzelm@16601
   704
        tpairs = tpairs,
wenzelm@16601
   705
        prop = all T $ Abs (a, T, abstract_over (x, prop))};
wenzelm@16601
   706
    fun check_occs x ts =
wenzelm@16847
   707
      if exists (fn t => Logic.occs (x, t)) ts then
wenzelm@16601
   708
        raise THM("forall_intr: variable free in assumptions", 0, [th])
wenzelm@16601
   709
      else ();
wenzelm@16601
   710
  in
wenzelm@16601
   711
    case x of
wenzelm@16601
   712
      Free (a, _) => (check_occs x hyps; check_occs x (terms_of_tpairs tpairs); result a)
wenzelm@16601
   713
    | Var ((a, _), _) => (check_occs x (terms_of_tpairs tpairs); result a)
wenzelm@16601
   714
    | _ => raise THM ("forall_intr: not a variable", 0, [th])
clasohm@0
   715
  end;
clasohm@0
   716
wenzelm@1220
   717
(*Forall elimination
wenzelm@16656
   718
  !!x. A
wenzelm@1220
   719
  ------
wenzelm@1220
   720
  A[t/x]
wenzelm@1220
   721
*)
wenzelm@16601
   722
fun forall_elim
wenzelm@16601
   723
    (ct as Cterm {t, T, maxidx = maxt, sorts, ...})
wenzelm@16601
   724
    (th as Thm {der, maxidx, shyps, hyps, tpairs, prop, ...}) =
wenzelm@16601
   725
  (case prop of
wenzelm@16601
   726
    Const ("all", Type ("fun", [Type ("fun", [qary, _]), _])) $ A =>
wenzelm@16601
   727
      if T <> qary then
wenzelm@16601
   728
        raise THM ("forall_elim: type mismatch", 0, [th])
wenzelm@16601
   729
      else
wenzelm@16601
   730
        Thm {thy_ref = merge_thys1 ct th,
wenzelm@16601
   731
          der = Pt.infer_derivs' (Pt.% o rpair (SOME t)) der,
wenzelm@16601
   732
          maxidx = Int.max (maxidx, maxt),
wenzelm@16601
   733
          shyps = Sorts.union sorts shyps,
wenzelm@16601
   734
          hyps = hyps,
wenzelm@16601
   735
          tpairs = tpairs,
wenzelm@16601
   736
          prop = Term.betapply (A, t)}
wenzelm@16601
   737
  | _ => raise THM ("forall_elim: not quantified", 0, [th]));
clasohm@0
   738
clasohm@0
   739
wenzelm@1220
   740
(* Equality *)
clasohm@0
   741
wenzelm@16601
   742
(*Reflexivity
wenzelm@16601
   743
  t == t
wenzelm@16601
   744
*)
wenzelm@16601
   745
fun reflexive (ct as Cterm {thy_ref, t, T, maxidx, sorts}) =
wenzelm@16656
   746
  Thm {thy_ref = thy_ref,
wenzelm@16601
   747
    der = Pt.infer_derivs' I (false, Pt.reflexive),
wenzelm@16601
   748
    maxidx = maxidx,
wenzelm@16601
   749
    shyps = sorts,
wenzelm@16601
   750
    hyps = [],
wenzelm@16601
   751
    tpairs = [],
wenzelm@16601
   752
    prop = Logic.mk_equals (t, t)};
clasohm@0
   753
wenzelm@16601
   754
(*Symmetry
wenzelm@16601
   755
  t == u
wenzelm@16601
   756
  ------
wenzelm@16601
   757
  u == t
wenzelm@1220
   758
*)
wenzelm@16601
   759
fun symmetric (th as Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@16601
   760
  (case prop of
wenzelm@16601
   761
    (eq as Const ("==", Type (_, [T, _]))) $ t $ u =>
wenzelm@16601
   762
      Thm {thy_ref = thy_ref,
wenzelm@16601
   763
        der = Pt.infer_derivs' Pt.symmetric der,
wenzelm@16601
   764
        maxidx = maxidx,
wenzelm@16601
   765
        shyps = shyps,
wenzelm@16601
   766
        hyps = hyps,
wenzelm@16601
   767
        tpairs = tpairs,
wenzelm@16601
   768
        prop = eq $ u $ t}
wenzelm@16601
   769
    | _ => raise THM ("symmetric", 0, [th]));
clasohm@0
   770
wenzelm@16601
   771
(*Transitivity
wenzelm@16601
   772
  t1 == u    u == t2
wenzelm@16601
   773
  ------------------
wenzelm@16601
   774
       t1 == t2
wenzelm@1220
   775
*)
clasohm@0
   776
fun transitive th1 th2 =
wenzelm@16601
   777
  let
wenzelm@16601
   778
    val Thm {der = der1, maxidx = max1, hyps = hyps1, shyps = shyps1, tpairs = tpairs1,
wenzelm@16601
   779
      prop = prop1, ...} = th1
wenzelm@16601
   780
    and Thm {der = der2, maxidx = max2, hyps = hyps2, shyps = shyps2, tpairs = tpairs2,
wenzelm@16601
   781
      prop = prop2, ...} = th2;
wenzelm@16601
   782
    fun err msg = raise THM ("transitive: " ^ msg, 0, [th1, th2]);
wenzelm@16601
   783
  in
wenzelm@16601
   784
    case (prop1, prop2) of
wenzelm@16601
   785
      ((eq as Const ("==", Type (_, [T, _]))) $ t1 $ u, Const ("==", _) $ u' $ t2) =>
wenzelm@16601
   786
        if not (u aconv u') then err "middle term"
wenzelm@16601
   787
        else
wenzelm@16656
   788
          Thm {thy_ref = merge_thys2 th1 th2,
wenzelm@16601
   789
            der = Pt.infer_derivs (Pt.transitive u T) der1 der2,
wenzelm@16601
   790
            maxidx = Int.max (max1, max2),
wenzelm@16601
   791
            shyps = Sorts.union shyps1 shyps2,
wenzelm@16601
   792
            hyps = union_hyps hyps1 hyps2,
wenzelm@16601
   793
            tpairs = union_tpairs tpairs1 tpairs2,
wenzelm@16601
   794
            prop = eq $ t1 $ t2}
wenzelm@16601
   795
     | _ =>  err "premises"
clasohm@0
   796
  end;
clasohm@0
   797
wenzelm@16601
   798
(*Beta-conversion
wenzelm@16656
   799
  (%x. t)(u) == t[u/x]
wenzelm@16601
   800
  fully beta-reduces the term if full = true
berghofe@10416
   801
*)
wenzelm@16601
   802
fun beta_conversion full (Cterm {thy_ref, t, T, maxidx, sorts}) =
wenzelm@16601
   803
  let val t' =
wenzelm@16601
   804
    if full then Envir.beta_norm t
wenzelm@16601
   805
    else
wenzelm@16601
   806
      (case t of Abs (_, _, bodt) $ u => subst_bound (u, bodt)
wenzelm@16601
   807
      | _ => raise THM ("beta_conversion: not a redex", 0, []));
wenzelm@16601
   808
  in
wenzelm@16601
   809
    Thm {thy_ref = thy_ref,
wenzelm@16601
   810
      der = Pt.infer_derivs' I (false, Pt.reflexive),
wenzelm@16601
   811
      maxidx = maxidx,
wenzelm@16601
   812
      shyps = sorts,
wenzelm@16601
   813
      hyps = [],
wenzelm@16601
   814
      tpairs = [],
wenzelm@16601
   815
      prop = Logic.mk_equals (t, t')}
berghofe@10416
   816
  end;
berghofe@10416
   817
wenzelm@16601
   818
fun eta_conversion (Cterm {thy_ref, t, T, maxidx, sorts}) =
wenzelm@16601
   819
  Thm {thy_ref = thy_ref,
wenzelm@16601
   820
    der = Pt.infer_derivs' I (false, Pt.reflexive),
wenzelm@16601
   821
    maxidx = maxidx,
wenzelm@16601
   822
    shyps = sorts,
wenzelm@16601
   823
    hyps = [],
wenzelm@16601
   824
    tpairs = [],
wenzelm@18944
   825
    prop = Logic.mk_equals (t, Envir.eta_contract t)};
clasohm@0
   826
clasohm@0
   827
(*The abstraction rule.  The Free or Var x must not be free in the hypotheses.
clasohm@0
   828
  The bound variable will be named "a" (since x will be something like x320)
wenzelm@16601
   829
      t == u
wenzelm@16601
   830
  --------------
wenzelm@16601
   831
  %x. t == %x. u
wenzelm@1220
   832
*)
wenzelm@16601
   833
fun abstract_rule a
wenzelm@16601
   834
    (Cterm {t = x, T, sorts, ...})
wenzelm@16601
   835
    (th as Thm {thy_ref, der, maxidx, hyps, shyps, tpairs, prop}) =
wenzelm@16601
   836
  let
wenzelm@17708
   837
    val string_of = Sign.string_of_term (Theory.deref thy_ref);
wenzelm@16601
   838
    val (t, u) = Logic.dest_equals prop
wenzelm@16601
   839
      handle TERM _ => raise THM ("abstract_rule: premise not an equality", 0, [th]);
wenzelm@16601
   840
    val result =
wenzelm@16601
   841
      Thm {thy_ref = thy_ref,
wenzelm@16601
   842
        der = Pt.infer_derivs' (Pt.abstract_rule x a) der,
wenzelm@16601
   843
        maxidx = maxidx,
wenzelm@16601
   844
        shyps = Sorts.union sorts shyps,
wenzelm@16601
   845
        hyps = hyps,
wenzelm@16601
   846
        tpairs = tpairs,
wenzelm@16601
   847
        prop = Logic.mk_equals
wenzelm@16601
   848
          (Abs (a, T, abstract_over (x, t)), Abs (a, T, abstract_over (x, u)))};
wenzelm@16601
   849
    fun check_occs x ts =
wenzelm@16847
   850
      if exists (fn t => Logic.occs (x, t)) ts then
wenzelm@17708
   851
        raise THM ("abstract_rule: variable free in assumptions " ^ string_of x, 0, [th])
wenzelm@16601
   852
      else ();
wenzelm@16601
   853
  in
wenzelm@16601
   854
    case x of
wenzelm@16601
   855
      Free _ => (check_occs x hyps; check_occs x (terms_of_tpairs tpairs); result)
wenzelm@16601
   856
    | Var _ => (check_occs x (terms_of_tpairs tpairs); result)
wenzelm@17708
   857
    | _ => raise THM ("abstract_rule: not a variable " ^ string_of x, 0, [th])
clasohm@0
   858
  end;
clasohm@0
   859
clasohm@0
   860
(*The combination rule
wenzelm@3529
   861
  f == g  t == u
wenzelm@3529
   862
  --------------
wenzelm@16601
   863
    f t == g u
wenzelm@1220
   864
*)
clasohm@0
   865
fun combination th1 th2 =
wenzelm@16601
   866
  let
wenzelm@16601
   867
    val Thm {der = der1, maxidx = max1, shyps = shyps1, hyps = hyps1, tpairs = tpairs1,
wenzelm@16601
   868
      prop = prop1, ...} = th1
wenzelm@16601
   869
    and Thm {der = der2, maxidx = max2, shyps = shyps2, hyps = hyps2, tpairs = tpairs2,
wenzelm@16601
   870
      prop = prop2, ...} = th2;
wenzelm@16601
   871
    fun chktypes fT tT =
wenzelm@16601
   872
      (case fT of
wenzelm@16601
   873
        Type ("fun", [T1, T2]) =>
wenzelm@16601
   874
          if T1 <> tT then
wenzelm@16601
   875
            raise THM ("combination: types", 0, [th1, th2])
wenzelm@16601
   876
          else ()
wenzelm@16601
   877
      | _ => raise THM ("combination: not function type", 0, [th1, th2]));
wenzelm@16601
   878
  in
wenzelm@16601
   879
    case (prop1, prop2) of
wenzelm@16601
   880
      (Const ("==", Type ("fun", [fT, _])) $ f $ g,
wenzelm@16601
   881
       Const ("==", Type ("fun", [tT, _])) $ t $ u) =>
wenzelm@16601
   882
        (chktypes fT tT;
wenzelm@16601
   883
          Thm {thy_ref = merge_thys2 th1 th2,
wenzelm@16601
   884
            der = Pt.infer_derivs (Pt.combination f g t u fT) der1 der2,
wenzelm@16601
   885
            maxidx = Int.max (max1, max2),
wenzelm@16601
   886
            shyps = Sorts.union shyps1 shyps2,
wenzelm@16601
   887
            hyps = union_hyps hyps1 hyps2,
wenzelm@16601
   888
            tpairs = union_tpairs tpairs1 tpairs2,
wenzelm@16601
   889
            prop = Logic.mk_equals (f $ t, g $ u)})
wenzelm@16601
   890
     | _ => raise THM ("combination: premises", 0, [th1, th2])
clasohm@0
   891
  end;
clasohm@0
   892
wenzelm@16601
   893
(*Equality introduction
wenzelm@3529
   894
  A ==> B  B ==> A
wenzelm@3529
   895
  ----------------
wenzelm@3529
   896
       A == B
wenzelm@1220
   897
*)
clasohm@0
   898
fun equal_intr th1 th2 =
wenzelm@16601
   899
  let
wenzelm@16601
   900
    val Thm {der = der1, maxidx = max1, shyps = shyps1, hyps = hyps1, tpairs = tpairs1,
wenzelm@16601
   901
      prop = prop1, ...} = th1
wenzelm@16601
   902
    and Thm {der = der2, maxidx = max2, shyps = shyps2, hyps = hyps2, tpairs = tpairs2,
wenzelm@16601
   903
      prop = prop2, ...} = th2;
wenzelm@16601
   904
    fun err msg = raise THM ("equal_intr: " ^ msg, 0, [th1, th2]);
wenzelm@16601
   905
  in
wenzelm@16601
   906
    case (prop1, prop2) of
wenzelm@16601
   907
      (Const("==>", _) $ A $ B, Const("==>", _) $ B' $ A') =>
wenzelm@16601
   908
        if A aconv A' andalso B aconv B' then
wenzelm@16601
   909
          Thm {thy_ref = merge_thys2 th1 th2,
wenzelm@16601
   910
            der = Pt.infer_derivs (Pt.equal_intr A B) der1 der2,
wenzelm@16601
   911
            maxidx = Int.max (max1, max2),
wenzelm@16601
   912
            shyps = Sorts.union shyps1 shyps2,
wenzelm@16601
   913
            hyps = union_hyps hyps1 hyps2,
wenzelm@16601
   914
            tpairs = union_tpairs tpairs1 tpairs2,
wenzelm@16601
   915
            prop = Logic.mk_equals (A, B)}
wenzelm@16601
   916
        else err "not equal"
wenzelm@16601
   917
    | _ =>  err "premises"
paulson@1529
   918
  end;
paulson@1529
   919
paulson@1529
   920
(*The equal propositions rule
wenzelm@3529
   921
  A == B  A
paulson@1529
   922
  ---------
paulson@1529
   923
      B
paulson@1529
   924
*)
paulson@1529
   925
fun equal_elim th1 th2 =
wenzelm@16601
   926
  let
wenzelm@16601
   927
    val Thm {der = der1, maxidx = max1, shyps = shyps1, hyps = hyps1,
wenzelm@16601
   928
      tpairs = tpairs1, prop = prop1, ...} = th1
wenzelm@16601
   929
    and Thm {der = der2, maxidx = max2, shyps = shyps2, hyps = hyps2,
wenzelm@16601
   930
      tpairs = tpairs2, prop = prop2, ...} = th2;
wenzelm@16601
   931
    fun err msg = raise THM ("equal_elim: " ^ msg, 0, [th1, th2]);
wenzelm@16601
   932
  in
wenzelm@16601
   933
    case prop1 of
wenzelm@16601
   934
      Const ("==", _) $ A $ B =>
wenzelm@16601
   935
        if prop2 aconv A then
wenzelm@16601
   936
          Thm {thy_ref = merge_thys2 th1 th2,
wenzelm@16601
   937
            der = Pt.infer_derivs (Pt.equal_elim A B) der1 der2,
wenzelm@16601
   938
            maxidx = Int.max (max1, max2),
wenzelm@16601
   939
            shyps = Sorts.union shyps1 shyps2,
wenzelm@16601
   940
            hyps = union_hyps hyps1 hyps2,
wenzelm@16601
   941
            tpairs = union_tpairs tpairs1 tpairs2,
wenzelm@16601
   942
            prop = B}
wenzelm@16601
   943
        else err "not equal"
paulson@1529
   944
     | _ =>  err"major premise"
paulson@1529
   945
  end;
clasohm@0
   946
wenzelm@1220
   947
wenzelm@1220
   948
clasohm@0
   949
(**** Derived rules ****)
clasohm@0
   950
wenzelm@16601
   951
(*Smash unifies the list of term pairs leaving no flex-flex pairs.
wenzelm@250
   952
  Instantiates the theorem and deletes trivial tpairs.
clasohm@0
   953
  Resulting sequence may contain multiple elements if the tpairs are
clasohm@0
   954
    not all flex-flex. *)
wenzelm@16601
   955
fun flexflex_rule (th as Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@19861
   956
  Unify.smash_unifiers (Theory.deref thy_ref) tpairs (Envir.empty maxidx)
wenzelm@16601
   957
  |> Seq.map (fn env =>
wenzelm@16601
   958
      if Envir.is_empty env then th
wenzelm@16601
   959
      else
wenzelm@16601
   960
        let
wenzelm@16601
   961
          val tpairs' = tpairs |> map (pairself (Envir.norm_term env))
wenzelm@16601
   962
            (*remove trivial tpairs, of the form t==t*)
wenzelm@16884
   963
            |> filter_out (op aconv);
wenzelm@16601
   964
          val prop' = Envir.norm_term env prop;
wenzelm@16601
   965
        in
wenzelm@16601
   966
          Thm {thy_ref = thy_ref,
wenzelm@16601
   967
            der = Pt.infer_derivs' (Pt.norm_proof' env) der,
wenzelm@16711
   968
            maxidx = maxidx_tpairs tpairs' (maxidx_of_term prop'),
wenzelm@16656
   969
            shyps = may_insert_env_sorts (Theory.deref thy_ref) env shyps,
wenzelm@16601
   970
            hyps = hyps,
wenzelm@16601
   971
            tpairs = tpairs',
wenzelm@16601
   972
            prop = prop'}
wenzelm@16601
   973
        end);
wenzelm@16601
   974
clasohm@0
   975
clasohm@0
   976
(*Instantiation of Vars
wenzelm@16656
   977
           A
wenzelm@16656
   978
  --------------------
wenzelm@16656
   979
  A[t1/v1, ..., tn/vn]
wenzelm@1220
   980
*)
clasohm@0
   981
wenzelm@6928
   982
local
wenzelm@6928
   983
wenzelm@16425
   984
fun pretty_typing thy t T =
wenzelm@16425
   985
  Pretty.block [Sign.pretty_term thy t, Pretty.str " ::", Pretty.brk 1, Sign.pretty_typ thy T];
berghofe@15797
   986
wenzelm@16884
   987
fun add_inst (ct, cu) (thy_ref, sorts) =
wenzelm@6928
   988
  let
wenzelm@16884
   989
    val Cterm {t = t, T = T, ...} = ct
wenzelm@16884
   990
    and Cterm {t = u, T = U, sorts = sorts_u, ...} = cu;
wenzelm@16884
   991
    val thy_ref' = Theory.merge_refs (thy_ref, merge_thys0 ct cu);
wenzelm@16884
   992
    val sorts' = Sorts.union sorts_u sorts;
wenzelm@3967
   993
  in
wenzelm@16884
   994
    (case t of Var v =>
wenzelm@16884
   995
      if T = U then ((v, u), (thy_ref', sorts'))
wenzelm@16884
   996
      else raise TYPE (Pretty.string_of (Pretty.block
wenzelm@16884
   997
       [Pretty.str "instantiate: type conflict",
wenzelm@16884
   998
        Pretty.fbrk, pretty_typing (Theory.deref thy_ref') t T,
wenzelm@16884
   999
        Pretty.fbrk, pretty_typing (Theory.deref thy_ref') u U]), [T, U], [t, u])
wenzelm@16884
  1000
    | _ => raise TYPE (Pretty.string_of (Pretty.block
wenzelm@16884
  1001
       [Pretty.str "instantiate: not a variable",
wenzelm@16884
  1002
        Pretty.fbrk, Sign.pretty_term (Theory.deref thy_ref') t]), [], [t]))
clasohm@0
  1003
  end;
clasohm@0
  1004
wenzelm@16884
  1005
fun add_instT (cT, cU) (thy_ref, sorts) =
wenzelm@16656
  1006
  let
wenzelm@16884
  1007
    val Ctyp {T, thy_ref = thy_ref1, ...} = cT
wenzelm@16884
  1008
    and Ctyp {T = U, thy_ref = thy_ref2, sorts = sorts_U, ...} = cU;
wenzelm@16884
  1009
    val thy_ref' = Theory.merge_refs (thy_ref, Theory.merge_refs (thy_ref1, thy_ref2));
wenzelm@16884
  1010
    val thy' = Theory.deref thy_ref';
wenzelm@16884
  1011
    val sorts' = Sorts.union sorts_U sorts;
wenzelm@16656
  1012
  in
wenzelm@16884
  1013
    (case T of TVar (v as (_, S)) =>
wenzelm@17203
  1014
      if Sign.of_sort thy' (U, S) then ((v, U), (thy_ref', sorts'))
wenzelm@16656
  1015
      else raise TYPE ("Type not of sort " ^ Sign.string_of_sort thy' S, [U], [])
wenzelm@16656
  1016
    | _ => raise TYPE (Pretty.string_of (Pretty.block
berghofe@15797
  1017
        [Pretty.str "instantiate: not a type variable",
wenzelm@16656
  1018
         Pretty.fbrk, Sign.pretty_typ thy' T]), [T], []))
wenzelm@16656
  1019
  end;
clasohm@0
  1020
wenzelm@6928
  1021
in
wenzelm@6928
  1022
wenzelm@16601
  1023
(*Left-to-right replacements: ctpairs = [..., (vi, ti), ...].
clasohm@0
  1024
  Instantiates distinct Vars by terms of same type.
wenzelm@16601
  1025
  Does NOT normalize the resulting theorem!*)
paulson@1529
  1026
fun instantiate ([], []) th = th
wenzelm@16884
  1027
  | instantiate (instT, inst) th =
wenzelm@16656
  1028
      let
wenzelm@16884
  1029
        val Thm {thy_ref, der, hyps, shyps, tpairs, prop, ...} = th;
wenzelm@16884
  1030
        val (inst', (instT', (thy_ref', shyps'))) =
wenzelm@16884
  1031
          (thy_ref, shyps) |> fold_map add_inst inst ||> fold_map add_instT instT;
wenzelm@16884
  1032
        val subst = Term.instantiate (instT', inst');
wenzelm@16656
  1033
        val prop' = subst prop;
wenzelm@16884
  1034
        val tpairs' = map (pairself subst) tpairs;
wenzelm@16656
  1035
      in
wenzelm@16884
  1036
        if has_duplicates (fn ((v, _), (v', _)) => Term.eq_var (v, v')) inst' then
wenzelm@16656
  1037
          raise THM ("instantiate: variables not distinct", 0, [th])
wenzelm@16884
  1038
        else if has_duplicates (fn ((v, _), (v', _)) => Term.eq_tvar (v, v')) instT' then
wenzelm@16656
  1039
          raise THM ("instantiate: type variables not distinct", 0, [th])
wenzelm@16656
  1040
        else
wenzelm@16884
  1041
          Thm {thy_ref = thy_ref',
wenzelm@16884
  1042
            der = Pt.infer_derivs' (Pt.instantiate (instT', inst')) der,
wenzelm@16884
  1043
            maxidx = maxidx_tpairs tpairs' (maxidx_of_term prop'),
wenzelm@16656
  1044
            shyps = shyps',
wenzelm@16656
  1045
            hyps = hyps,
wenzelm@16884
  1046
            tpairs = tpairs',
wenzelm@16656
  1047
            prop = prop'}
wenzelm@16656
  1048
      end
wenzelm@16656
  1049
      handle TYPE (msg, _, _) => raise THM (msg, 0, [th]);
wenzelm@6928
  1050
wenzelm@6928
  1051
end;
wenzelm@6928
  1052
clasohm@0
  1053
wenzelm@16601
  1054
(*The trivial implication A ==> A, justified by assume and forall rules.
wenzelm@16601
  1055
  A can contain Vars, not so for assume!*)
wenzelm@16601
  1056
fun trivial (Cterm {thy_ref, t =A, T, maxidx, sorts}) =
wenzelm@16601
  1057
  if T <> propT then
wenzelm@16601
  1058
    raise THM ("trivial: the term must have type prop", 0, [])
wenzelm@16601
  1059
  else
wenzelm@16601
  1060
    Thm {thy_ref = thy_ref,
wenzelm@16601
  1061
      der = Pt.infer_derivs' I (false, Pt.AbsP ("H", NONE, Pt.PBound 0)),
wenzelm@16601
  1062
      maxidx = maxidx,
wenzelm@16601
  1063
      shyps = sorts,
wenzelm@16601
  1064
      hyps = [],
wenzelm@16601
  1065
      tpairs = [],
wenzelm@16601
  1066
      prop = implies $ A $ A};
clasohm@0
  1067
paulson@1503
  1068
(*Axiom-scheme reflecting signature contents: "OFCLASS(?'a::c, c_class)" *)
wenzelm@16425
  1069
fun class_triv thy c =
wenzelm@16601
  1070
  let val Cterm {thy_ref, t, maxidx, sorts, ...} =
wenzelm@19525
  1071
    cterm_of thy (Logic.mk_inclass (TVar (("'a", 0), [c]), Sign.certify_class thy c))
wenzelm@6368
  1072
      handle TERM (msg, _) => raise THM ("class_triv: " ^ msg, 0, []);
wenzelm@399
  1073
  in
wenzelm@16601
  1074
    Thm {thy_ref = thy_ref,
wenzelm@16601
  1075
      der = Pt.infer_derivs' I (false, Pt.PAxm ("ProtoPure.class_triv:" ^ c, t, SOME [])),
wenzelm@16601
  1076
      maxidx = maxidx,
wenzelm@16601
  1077
      shyps = sorts,
wenzelm@16601
  1078
      hyps = [],
wenzelm@16601
  1079
      tpairs = [],
wenzelm@16601
  1080
      prop = t}
wenzelm@399
  1081
  end;
wenzelm@399
  1082
wenzelm@19505
  1083
(*Internalize sort constraints of type variable*)
wenzelm@19505
  1084
fun unconstrainT
wenzelm@19505
  1085
    (Ctyp {thy_ref = thy_ref1, T, ...})
wenzelm@19505
  1086
    (th as Thm {thy_ref = thy_ref2, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@19505
  1087
  let
wenzelm@19505
  1088
    val ((x, i), S) = Term.dest_TVar T handle TYPE _ =>
wenzelm@19505
  1089
      raise THM ("unconstrainT: not a type variable", 0, [th]);
wenzelm@19505
  1090
    val T' = TVar ((x, i), []);
wenzelm@19505
  1091
    val unconstrain = Term.map_term_types (Term.map_atyps (fn U => if U = T then T' else U));
wenzelm@19505
  1092
    val constraints = map (curry Logic.mk_inclass T') S;
wenzelm@19505
  1093
  in
wenzelm@19505
  1094
    Thm {thy_ref = Theory.merge_refs (thy_ref1, thy_ref2),
wenzelm@19505
  1095
      der = Pt.infer_derivs' I (false, Pt.PAxm ("ProtoPure.unconstrainT", prop, SOME [])),
wenzelm@19505
  1096
      maxidx = Int.max (maxidx, i),
wenzelm@19505
  1097
      shyps = Sorts.remove_sort S shyps,
wenzelm@19505
  1098
      hyps = hyps,
wenzelm@19505
  1099
      tpairs = map (pairself unconstrain) tpairs,
wenzelm@19505
  1100
      prop = Logic.list_implies (constraints, unconstrain prop)}
wenzelm@19505
  1101
  end;
wenzelm@399
  1102
wenzelm@6786
  1103
(* Replace all TFrees not fixed or in the hyps by new TVars *)
wenzelm@16601
  1104
fun varifyT' fixed (Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@12500
  1105
  let
berghofe@15797
  1106
    val tfrees = foldr add_term_tfrees fixed hyps;
berghofe@13658
  1107
    val prop1 = attach_tpairs tpairs prop;
berghofe@13658
  1108
    val (prop2, al) = Type.varify (prop1, tfrees);
wenzelm@16601
  1109
    val (ts, prop3) = Logic.strip_prems (length tpairs, [], prop2);
wenzelm@16601
  1110
  in
wenzelm@18127
  1111
    (al, Thm {thy_ref = thy_ref,
wenzelm@16601
  1112
      der = Pt.infer_derivs' (Pt.varify_proof prop tfrees) der,
wenzelm@16601
  1113
      maxidx = Int.max (0, maxidx),
wenzelm@16601
  1114
      shyps = shyps,
wenzelm@16601
  1115
      hyps = hyps,
wenzelm@16601
  1116
      tpairs = rev (map Logic.dest_equals ts),
wenzelm@18127
  1117
      prop = prop3})
clasohm@0
  1118
  end;
clasohm@0
  1119
wenzelm@18127
  1120
val varifyT = #2 o varifyT' [];
wenzelm@6786
  1121
clasohm@0
  1122
(* Replace all TVars by new TFrees *)
wenzelm@16601
  1123
fun freezeT (Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
berghofe@13658
  1124
  let
berghofe@13658
  1125
    val prop1 = attach_tpairs tpairs prop;
wenzelm@16287
  1126
    val prop2 = Type.freeze prop1;
wenzelm@16601
  1127
    val (ts, prop3) = Logic.strip_prems (length tpairs, [], prop2);
wenzelm@16601
  1128
  in
wenzelm@16601
  1129
    Thm {thy_ref = thy_ref,
wenzelm@16601
  1130
      der = Pt.infer_derivs' (Pt.freezeT prop1) der,
wenzelm@16601
  1131
      maxidx = maxidx_of_term prop2,
wenzelm@16601
  1132
      shyps = shyps,
wenzelm@16601
  1133
      hyps = hyps,
wenzelm@16601
  1134
      tpairs = rev (map Logic.dest_equals ts),
wenzelm@16601
  1135
      prop = prop3}
wenzelm@1220
  1136
  end;
clasohm@0
  1137
clasohm@0
  1138
clasohm@0
  1139
(*** Inference rules for tactics ***)
clasohm@0
  1140
clasohm@0
  1141
(*Destruct proof state into constraints, other goals, goal(i), rest *)
berghofe@13658
  1142
fun dest_state (state as Thm{prop,tpairs,...}, i) =
berghofe@13658
  1143
  (case  Logic.strip_prems(i, [], prop) of
berghofe@13658
  1144
      (B::rBs, C) => (tpairs, rev rBs, B, C)
berghofe@13658
  1145
    | _ => raise THM("dest_state", i, [state]))
clasohm@0
  1146
  handle TERM _ => raise THM("dest_state", i, [state]);
clasohm@0
  1147
lcp@309
  1148
(*Increment variables and parameters of orule as required for
wenzelm@18035
  1149
  resolution with a goal.*)
wenzelm@18035
  1150
fun lift_rule goal orule =
wenzelm@16601
  1151
  let
wenzelm@18035
  1152
    val Cterm {t = gprop, T, maxidx = gmax, sorts, ...} = goal;
wenzelm@18035
  1153
    val inc = gmax + 1;
wenzelm@18035
  1154
    val lift_abs = Logic.lift_abs inc gprop;
wenzelm@18035
  1155
    val lift_all = Logic.lift_all inc gprop;
wenzelm@18035
  1156
    val Thm {der, maxidx, shyps, hyps, tpairs, prop, ...} = orule;
wenzelm@16601
  1157
    val (As, B) = Logic.strip_horn prop;
wenzelm@16601
  1158
  in
wenzelm@18035
  1159
    if T <> propT then raise THM ("lift_rule: the term must have type prop", 0, [])
wenzelm@18035
  1160
    else
wenzelm@18035
  1161
      Thm {thy_ref = merge_thys1 goal orule,
wenzelm@18035
  1162
        der = Pt.infer_derivs' (Pt.lift_proof gprop inc prop) der,
wenzelm@18035
  1163
        maxidx = maxidx + inc,
wenzelm@18035
  1164
        shyps = Sorts.union shyps sorts,  (*sic!*)
wenzelm@18035
  1165
        hyps = hyps,
wenzelm@18035
  1166
        tpairs = map (pairself lift_abs) tpairs,
wenzelm@18035
  1167
        prop = Logic.list_implies (map lift_all As, lift_all B)}
clasohm@0
  1168
  end;
clasohm@0
  1169
wenzelm@16425
  1170
fun incr_indexes i (thm as Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@16601
  1171
  if i < 0 then raise THM ("negative increment", 0, [thm])
wenzelm@16601
  1172
  else if i = 0 then thm
wenzelm@16601
  1173
  else
wenzelm@16425
  1174
    Thm {thy_ref = thy_ref,
wenzelm@16884
  1175
      der = Pt.infer_derivs'
wenzelm@16884
  1176
        (Pt.map_proof_terms (Logic.incr_indexes ([], i)) (Logic.incr_tvar i)) der,
wenzelm@16601
  1177
      maxidx = maxidx + i,
wenzelm@16601
  1178
      shyps = shyps,
wenzelm@16601
  1179
      hyps = hyps,
wenzelm@16601
  1180
      tpairs = map (pairself (Logic.incr_indexes ([], i))) tpairs,
wenzelm@16601
  1181
      prop = Logic.incr_indexes ([], i) prop};
berghofe@10416
  1182
clasohm@0
  1183
(*Solve subgoal Bi of proof state B1...Bn/C by assumption. *)
clasohm@0
  1184
fun assumption i state =
wenzelm@16601
  1185
  let
wenzelm@16601
  1186
    val Thm {thy_ref, der, maxidx, shyps, hyps, prop, ...} = state;
wenzelm@16656
  1187
    val thy = Theory.deref thy_ref;
wenzelm@16601
  1188
    val (tpairs, Bs, Bi, C) = dest_state (state, i);
wenzelm@16601
  1189
    fun newth n (env as Envir.Envir {maxidx, ...}, tpairs) =
wenzelm@16601
  1190
      Thm {thy_ref = thy_ref,
wenzelm@16601
  1191
        der = Pt.infer_derivs'
wenzelm@16601
  1192
          ((if Envir.is_empty env then I else (Pt.norm_proof' env)) o
wenzelm@16601
  1193
            Pt.assumption_proof Bs Bi n) der,
wenzelm@16601
  1194
        maxidx = maxidx,
wenzelm@16656
  1195
        shyps = may_insert_env_sorts thy env shyps,
wenzelm@16601
  1196
        hyps = hyps,
wenzelm@16601
  1197
        tpairs =
wenzelm@16601
  1198
          if Envir.is_empty env then tpairs
wenzelm@16601
  1199
          else map (pairself (Envir.norm_term env)) tpairs,
wenzelm@16601
  1200
        prop =
wenzelm@16601
  1201
          if Envir.is_empty env then (*avoid wasted normalizations*)
wenzelm@16601
  1202
            Logic.list_implies (Bs, C)
wenzelm@16601
  1203
          else (*normalize the new rule fully*)
wenzelm@16601
  1204
            Envir.norm_term env (Logic.list_implies (Bs, C))};
wenzelm@16601
  1205
    fun addprfs [] _ = Seq.empty
wenzelm@16601
  1206
      | addprfs ((t, u) :: apairs) n = Seq.make (fn () => Seq.pull
wenzelm@16601
  1207
          (Seq.mapp (newth n)
wenzelm@16656
  1208
            (Unify.unifiers (thy, Envir.empty maxidx, (t, u) :: tpairs))
wenzelm@16601
  1209
            (addprfs apairs (n + 1))))
wenzelm@16601
  1210
  in addprfs (Logic.assum_pairs (~1, Bi)) 1 end;
clasohm@0
  1211
wenzelm@250
  1212
(*Solve subgoal Bi of proof state B1...Bn/C by assumption.
clasohm@0
  1213
  Checks if Bi's conclusion is alpha-convertible to one of its assumptions*)
clasohm@0
  1214
fun eq_assumption i state =
wenzelm@16601
  1215
  let
wenzelm@16601
  1216
    val Thm {thy_ref, der, maxidx, shyps, hyps, prop, ...} = state;
wenzelm@16601
  1217
    val (tpairs, Bs, Bi, C) = dest_state (state, i);
wenzelm@16601
  1218
  in
wenzelm@16601
  1219
    (case find_index (op aconv) (Logic.assum_pairs (~1, Bi)) of
wenzelm@16601
  1220
      ~1 => raise THM ("eq_assumption", 0, [state])
wenzelm@16601
  1221
    | n =>
wenzelm@16601
  1222
        Thm {thy_ref = thy_ref,
wenzelm@16601
  1223
          der = Pt.infer_derivs' (Pt.assumption_proof Bs Bi (n + 1)) der,
wenzelm@16601
  1224
          maxidx = maxidx,
wenzelm@16601
  1225
          shyps = shyps,
wenzelm@16601
  1226
          hyps = hyps,
wenzelm@16601
  1227
          tpairs = tpairs,
wenzelm@16601
  1228
          prop = Logic.list_implies (Bs, C)})
clasohm@0
  1229
  end;
clasohm@0
  1230
clasohm@0
  1231
paulson@2671
  1232
(*For rotate_tac: fast rotation of assumptions of subgoal i*)
paulson@2671
  1233
fun rotate_rule k i state =
wenzelm@16601
  1234
  let
wenzelm@16601
  1235
    val Thm {thy_ref, der, maxidx, shyps, hyps, prop, ...} = state;
wenzelm@16601
  1236
    val (tpairs, Bs, Bi, C) = dest_state (state, i);
wenzelm@16601
  1237
    val params = Term.strip_all_vars Bi
wenzelm@16601
  1238
    and rest   = Term.strip_all_body Bi;
wenzelm@16601
  1239
    val asms   = Logic.strip_imp_prems rest
wenzelm@16601
  1240
    and concl  = Logic.strip_imp_concl rest;
wenzelm@16601
  1241
    val n = length asms;
wenzelm@16601
  1242
    val m = if k < 0 then n + k else k;
wenzelm@16601
  1243
    val Bi' =
wenzelm@16601
  1244
      if 0 = m orelse m = n then Bi
wenzelm@16601
  1245
      else if 0 < m andalso m < n then
wenzelm@19012
  1246
        let val (ps, qs) = chop m asms
wenzelm@16601
  1247
        in list_all (params, Logic.list_implies (qs @ ps, concl)) end
wenzelm@16601
  1248
      else raise THM ("rotate_rule", k, [state]);
wenzelm@16601
  1249
  in
wenzelm@16601
  1250
    Thm {thy_ref = thy_ref,
wenzelm@16601
  1251
      der = Pt.infer_derivs' (Pt.rotate_proof Bs Bi m) der,
wenzelm@16601
  1252
      maxidx = maxidx,
wenzelm@16601
  1253
      shyps = shyps,
wenzelm@16601
  1254
      hyps = hyps,
wenzelm@16601
  1255
      tpairs = tpairs,
wenzelm@16601
  1256
      prop = Logic.list_implies (Bs @ [Bi'], C)}
paulson@2671
  1257
  end;
paulson@2671
  1258
paulson@2671
  1259
paulson@7248
  1260
(*Rotates a rule's premises to the left by k, leaving the first j premises
paulson@7248
  1261
  unchanged.  Does nothing if k=0 or if k equals n-j, where n is the
wenzelm@16656
  1262
  number of premises.  Useful with etac and underlies defer_tac*)
paulson@7248
  1263
fun permute_prems j k rl =
wenzelm@16601
  1264
  let
wenzelm@16601
  1265
    val Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop} = rl;
wenzelm@16601
  1266
    val prems = Logic.strip_imp_prems prop
wenzelm@16601
  1267
    and concl = Logic.strip_imp_concl prop;
wenzelm@16601
  1268
    val moved_prems = List.drop (prems, j)
wenzelm@16601
  1269
    and fixed_prems = List.take (prems, j)
wenzelm@16601
  1270
      handle Subscript => raise THM ("permute_prems: j", j, [rl]);
wenzelm@16601
  1271
    val n_j = length moved_prems;
wenzelm@16601
  1272
    val m = if k < 0 then n_j + k else k;
wenzelm@16601
  1273
    val prop' =
wenzelm@16601
  1274
      if 0 = m orelse m = n_j then prop
wenzelm@16601
  1275
      else if 0 < m andalso m < n_j then
wenzelm@19012
  1276
        let val (ps, qs) = chop m moved_prems
wenzelm@16601
  1277
        in Logic.list_implies (fixed_prems @ qs @ ps, concl) end
wenzelm@16725
  1278
      else raise THM ("permute_prems: k", k, [rl]);
wenzelm@16601
  1279
  in
wenzelm@16601
  1280
    Thm {thy_ref = thy_ref,
wenzelm@16601
  1281
      der = Pt.infer_derivs' (Pt.permute_prems_prf prems j m) der,
wenzelm@16601
  1282
      maxidx = maxidx,
wenzelm@16601
  1283
      shyps = shyps,
wenzelm@16601
  1284
      hyps = hyps,
wenzelm@16601
  1285
      tpairs = tpairs,
wenzelm@16601
  1286
      prop = prop'}
paulson@7248
  1287
  end;
paulson@7248
  1288
paulson@7248
  1289
clasohm@0
  1290
(** User renaming of parameters in a subgoal **)
clasohm@0
  1291
clasohm@0
  1292
(*Calls error rather than raising an exception because it is intended
clasohm@0
  1293
  for top-level use -- exception handling would not make sense here.
clasohm@0
  1294
  The names in cs, if distinct, are used for the innermost parameters;
wenzelm@17868
  1295
  preceding parameters may be renamed to make all params distinct.*)
clasohm@0
  1296
fun rename_params_rule (cs, i) state =
wenzelm@16601
  1297
  let
wenzelm@16601
  1298
    val Thm {thy_ref, der, maxidx, shyps, hyps, ...} = state;
wenzelm@16601
  1299
    val (tpairs, Bs, Bi, C) = dest_state (state, i);
wenzelm@16601
  1300
    val iparams = map #1 (Logic.strip_params Bi);
wenzelm@16601
  1301
    val short = length iparams - length cs;
wenzelm@16601
  1302
    val newnames =
wenzelm@16601
  1303
      if short < 0 then error "More names than abstractions!"
wenzelm@16601
  1304
      else variantlist (Library.take (short, iparams), cs) @ cs;
wenzelm@16601
  1305
    val freenames = map (#1 o dest_Free) (term_frees Bi);
wenzelm@16601
  1306
    val newBi = Logic.list_rename_params (newnames, Bi);
wenzelm@250
  1307
  in
wenzelm@16601
  1308
    case findrep cs of
wenzelm@16601
  1309
      c :: _ => (warning ("Can't rename.  Bound variables not distinct: " ^ c); state)
wenzelm@16601
  1310
    | [] =>
wenzelm@16601
  1311
      (case cs inter_string freenames of
wenzelm@16601
  1312
        a :: _ => (warning ("Can't rename.  Bound/Free variable clash: " ^ a); state)
wenzelm@16601
  1313
      | [] =>
wenzelm@16601
  1314
        Thm {thy_ref = thy_ref,
wenzelm@16601
  1315
          der = der,
wenzelm@16601
  1316
          maxidx = maxidx,
wenzelm@16601
  1317
          shyps = shyps,
wenzelm@16601
  1318
          hyps = hyps,
wenzelm@16601
  1319
          tpairs = tpairs,
wenzelm@16601
  1320
          prop = Logic.list_implies (Bs @ [newBi], C)})
clasohm@0
  1321
  end;
clasohm@0
  1322
wenzelm@12982
  1323
clasohm@0
  1324
(*** Preservation of bound variable names ***)
clasohm@0
  1325
wenzelm@16601
  1326
fun rename_boundvars pat obj (thm as Thm {thy_ref, der, maxidx, shyps, hyps, tpairs, prop}) =
wenzelm@12982
  1327
  (case Term.rename_abs pat obj prop of
skalberg@15531
  1328
    NONE => thm
skalberg@15531
  1329
  | SOME prop' => Thm
wenzelm@16425
  1330
      {thy_ref = thy_ref,
wenzelm@12982
  1331
       der = der,
wenzelm@12982
  1332
       maxidx = maxidx,
wenzelm@12982
  1333
       hyps = hyps,
wenzelm@12982
  1334
       shyps = shyps,
berghofe@13658
  1335
       tpairs = tpairs,
wenzelm@12982
  1336
       prop = prop'});
berghofe@10416
  1337
clasohm@0
  1338
wenzelm@16656
  1339
(* strip_apply f (A, B) strips off all assumptions/parameters from A
clasohm@0
  1340
   introduced by lifting over B, and applies f to remaining part of A*)
clasohm@0
  1341
fun strip_apply f =
clasohm@0
  1342
  let fun strip(Const("==>",_)$ A1 $ B1,
wenzelm@250
  1343
                Const("==>",_)$ _  $ B2) = implies $ A1 $ strip(B1,B2)
wenzelm@250
  1344
        | strip((c as Const("all",_)) $ Abs(a,T,t1),
wenzelm@250
  1345
                      Const("all",_)  $ Abs(_,_,t2)) = c$Abs(a,T,strip(t1,t2))
wenzelm@250
  1346
        | strip(A,_) = f A
clasohm@0
  1347
  in strip end;
clasohm@0
  1348
clasohm@0
  1349
(*Use the alist to rename all bound variables and some unknowns in a term
clasohm@0
  1350
  dpairs = current disagreement pairs;  tpairs = permanent ones (flexflex);
clasohm@0
  1351
  Preserves unknowns in tpairs and on lhs of dpairs. *)
clasohm@0
  1352
fun rename_bvs([],_,_,_) = I
clasohm@0
  1353
  | rename_bvs(al,dpairs,tpairs,B) =
skalberg@15574
  1354
    let val vars = foldr add_term_vars []
skalberg@15574
  1355
                        (map fst dpairs @ map fst tpairs @ map snd tpairs)
wenzelm@250
  1356
        (*unknowns appearing elsewhere be preserved!*)
wenzelm@250
  1357
        val vids = map (#1 o #1 o dest_Var) vars;
wenzelm@250
  1358
        fun rename(t as Var((x,i),T)) =
wenzelm@17184
  1359
                (case AList.lookup (op =) al x of
skalberg@15531
  1360
                   SOME(y) => if x mem_string vids orelse y mem_string vids then t
wenzelm@250
  1361
                              else Var((y,i),T)
skalberg@15531
  1362
                 | NONE=> t)
clasohm@0
  1363
          | rename(Abs(x,T,t)) =
wenzelm@18944
  1364
              Abs (the_default x (AList.lookup (op =) al x), T, rename t)
clasohm@0
  1365
          | rename(f$t) = rename f $ rename t
clasohm@0
  1366
          | rename(t) = t;
wenzelm@250
  1367
        fun strip_ren Ai = strip_apply rename (Ai,B)
clasohm@0
  1368
    in strip_ren end;
clasohm@0
  1369
clasohm@0
  1370
(*Function to rename bounds/unknowns in the argument, lifted over B*)
clasohm@0
  1371
fun rename_bvars(dpairs, tpairs, B) =
skalberg@15574
  1372
        rename_bvs(foldr Term.match_bvars [] dpairs, dpairs, tpairs, B);
clasohm@0
  1373
clasohm@0
  1374
clasohm@0
  1375
(*** RESOLUTION ***)
clasohm@0
  1376
lcp@721
  1377
(** Lifting optimizations **)
lcp@721
  1378
clasohm@0
  1379
(*strip off pairs of assumptions/parameters in parallel -- they are
clasohm@0
  1380
  identical because of lifting*)
wenzelm@250
  1381
fun strip_assums2 (Const("==>", _) $ _ $ B1,
wenzelm@250
  1382
                   Const("==>", _) $ _ $ B2) = strip_assums2 (B1,B2)
clasohm@0
  1383
  | strip_assums2 (Const("all",_)$Abs(a,T,t1),
wenzelm@250
  1384
                   Const("all",_)$Abs(_,_,t2)) =
clasohm@0
  1385
      let val (B1,B2) = strip_assums2 (t1,t2)
clasohm@0
  1386
      in  (Abs(a,T,B1), Abs(a,T,B2))  end
clasohm@0
  1387
  | strip_assums2 BB = BB;
clasohm@0
  1388
clasohm@0
  1389
lcp@721
  1390
(*Faster normalization: skip assumptions that were lifted over*)
lcp@721
  1391
fun norm_term_skip env 0 t = Envir.norm_term env t
lcp@721
  1392
  | norm_term_skip env n (Const("all",_)$Abs(a,T,t)) =
lcp@721
  1393
        let val Envir.Envir{iTs, ...} = env
berghofe@15797
  1394
            val T' = Envir.typ_subst_TVars iTs T
wenzelm@1238
  1395
            (*Must instantiate types of parameters because they are flattened;
lcp@721
  1396
              this could be a NEW parameter*)
lcp@721
  1397
        in  all T' $ Abs(a, T', norm_term_skip env n t)  end
lcp@721
  1398
  | norm_term_skip env n (Const("==>", _) $ A $ B) =
wenzelm@1238
  1399
        implies $ A $ norm_term_skip env (n-1) B
lcp@721
  1400
  | norm_term_skip env n t = error"norm_term_skip: too few assumptions??";
lcp@721
  1401
lcp@721
  1402
clasohm@0
  1403
(*Composition of object rule r=(A1...Am/B) with proof state s=(B1...Bn/C)
wenzelm@250
  1404
  Unifies B with Bi, replacing subgoal i    (1 <= i <= n)
clasohm@0
  1405
  If match then forbid instantiations in proof state
clasohm@0
  1406
  If lifted then shorten the dpair using strip_assums2.
clasohm@0
  1407
  If eres_flg then simultaneously proves A1 by assumption.
wenzelm@250
  1408
  nsubgoal is the number of new subgoals (written m above).
clasohm@0
  1409
  Curried so that resolution calls dest_state only once.
clasohm@0
  1410
*)
wenzelm@4270
  1411
local exception COMPOSE
clasohm@0
  1412
in
wenzelm@18486
  1413
fun bicompose_aux flatten match (state, (stpairs, Bs, Bi, C), lifted)
clasohm@0
  1414
                        (eres_flg, orule, nsubgoal) =
paulson@1529
  1415
 let val Thm{der=sder, maxidx=smax, shyps=sshyps, hyps=shyps, ...} = state
wenzelm@16425
  1416
     and Thm{der=rder, maxidx=rmax, shyps=rshyps, hyps=rhyps,
berghofe@13658
  1417
             tpairs=rtpairs, prop=rprop,...} = orule
paulson@1529
  1418
         (*How many hyps to skip over during normalization*)
wenzelm@1238
  1419
     and nlift = Logic.count_prems(strip_all_body Bi,
wenzelm@1238
  1420
                                   if eres_flg then ~1 else 0)
wenzelm@16601
  1421
     val thy_ref = merge_thys2 state orule;
wenzelm@16425
  1422
     val thy = Theory.deref thy_ref;
clasohm@0
  1423
     (** Add new theorem with prop = '[| Bs; As |] ==> C' to thq **)
berghofe@11518
  1424
     fun addth A (As, oldAs, rder', n) ((env as Envir.Envir {maxidx, ...}, tpairs), thq) =
wenzelm@250
  1425
       let val normt = Envir.norm_term env;
wenzelm@250
  1426
           (*perform minimal copying here by examining env*)
berghofe@13658
  1427
           val (ntpairs, normp) =
berghofe@13658
  1428
             if Envir.is_empty env then (tpairs, (Bs @ As, C))
wenzelm@250
  1429
             else
wenzelm@250
  1430
             let val ntps = map (pairself normt) tpairs
wenzelm@19861
  1431
             in if Envir.above env smax then
wenzelm@1238
  1432
                  (*no assignments in state; normalize the rule only*)
wenzelm@1238
  1433
                  if lifted
berghofe@13658
  1434
                  then (ntps, (Bs @ map (norm_term_skip env nlift) As, C))
berghofe@13658
  1435
                  else (ntps, (Bs @ map normt As, C))
paulson@1529
  1436
                else if match then raise COMPOSE
wenzelm@250
  1437
                else (*normalize the new rule fully*)
berghofe@13658
  1438
                  (ntps, (map normt (Bs @ As), normt C))
wenzelm@250
  1439
             end
wenzelm@16601
  1440
           val th =
wenzelm@16425
  1441
             Thm{thy_ref = thy_ref,
berghofe@11518
  1442
                 der = Pt.infer_derivs
berghofe@11518
  1443
                   ((if Envir.is_empty env then I
wenzelm@19861
  1444
                     else if Envir.above env smax then
berghofe@11518
  1445
                       (fn f => fn der => f (Pt.norm_proof' env der))
berghofe@11518
  1446
                     else
berghofe@11518
  1447
                       curry op oo (Pt.norm_proof' env))
wenzelm@18486
  1448
                    (Pt.bicompose_proof flatten Bs oldAs As A n)) rder' sder,
wenzelm@2386
  1449
                 maxidx = maxidx,
wenzelm@16656
  1450
                 shyps = may_insert_env_sorts thy env (Sorts.union rshyps sshyps),
wenzelm@16601
  1451
                 hyps = union_hyps rhyps shyps,
berghofe@13658
  1452
                 tpairs = ntpairs,
berghofe@13658
  1453
                 prop = Logic.list_implies normp}
wenzelm@19475
  1454
        in  Seq.cons th thq  end  handle COMPOSE => thq;
berghofe@13658
  1455
     val (rAs,B) = Logic.strip_prems(nsubgoal, [], rprop)
clasohm@0
  1456
       handle TERM _ => raise THM("bicompose: rule", 0, [orule,state]);
clasohm@0
  1457
     (*Modify assumptions, deleting n-th if n>0 for e-resolution*)
clasohm@0
  1458
     fun newAs(As0, n, dpairs, tpairs) =
berghofe@11518
  1459
       let val (As1, rder') =
berghofe@11518
  1460
         if !Logic.auto_rename orelse not lifted then (As0, rder)
berghofe@11518
  1461
         else (map (rename_bvars(dpairs,tpairs,B)) As0,
berghofe@11518
  1462
           Pt.infer_derivs' (Pt.map_proof_terms
berghofe@11518
  1463
             (rename_bvars (dpairs, tpairs, Bound 0)) I) rder);
wenzelm@18486
  1464
       in (map (if flatten then (Logic.flatten_params n) else I) As1, As1, rder', n)
wenzelm@250
  1465
          handle TERM _ =>
wenzelm@250
  1466
          raise THM("bicompose: 1st premise", 0, [orule])
clasohm@0
  1467
       end;
paulson@2147
  1468
     val env = Envir.empty(Int.max(rmax,smax));
clasohm@0
  1469
     val BBi = if lifted then strip_assums2(B,Bi) else (B,Bi);
clasohm@0
  1470
     val dpairs = BBi :: (rtpairs@stpairs);
clasohm@0
  1471
     (*elim-resolution: try each assumption in turn.  Initially n=1*)
berghofe@11518
  1472
     fun tryasms (_, _, _, []) = Seq.empty
berghofe@11518
  1473
       | tryasms (A, As, n, (t,u)::apairs) =
wenzelm@16425
  1474
          (case Seq.pull(Unify.unifiers(thy, env, (t,u)::dpairs))  of
wenzelm@16425
  1475
              NONE                   => tryasms (A, As, n+1, apairs)
wenzelm@16425
  1476
            | cell as SOME((_,tpairs),_) =>
wenzelm@16425
  1477
                Seq.it_right (addth A (newAs(As, n, [BBi,(u,t)], tpairs)))
wenzelm@16425
  1478
                    (Seq.make(fn()=> cell),
wenzelm@16425
  1479
                     Seq.make(fn()=> Seq.pull (tryasms(A, As, n+1, apairs)))))
clasohm@0
  1480
     fun eres [] = raise THM("bicompose: no premises", 0, [orule,state])
skalberg@15531
  1481
       | eres (A1::As) = tryasms(SOME A1, As, 1, Logic.assum_pairs(nlift+1,A1))
clasohm@0
  1482
     (*ordinary resolution*)
skalberg@15531
  1483
     fun res(NONE) = Seq.empty
skalberg@15531
  1484
       | res(cell as SOME((_,tpairs),_)) =
skalberg@15531
  1485
             Seq.it_right (addth NONE (newAs(rev rAs, 0, [BBi], tpairs)))
wenzelm@4270
  1486
                       (Seq.make (fn()=> cell), Seq.empty)
clasohm@0
  1487
 in  if eres_flg then eres(rev rAs)
wenzelm@16425
  1488
     else res(Seq.pull(Unify.unifiers(thy, env, dpairs)))
clasohm@0
  1489
 end;
wenzelm@7528
  1490
end;
clasohm@0
  1491
wenzelm@18501
  1492
fun compose_no_flatten match (orule, nsubgoal) i state =
wenzelm@18501
  1493
  bicompose_aux false match (state, dest_state (state, i), false) (false, orule, nsubgoal);
clasohm@0
  1494
wenzelm@18501
  1495
fun bicompose match arg i state =
wenzelm@18501
  1496
  bicompose_aux true match (state, dest_state (state,i), false) arg;
clasohm@0
  1497
clasohm@0
  1498
(*Quick test whether rule is resolvable with the subgoal with hyps Hs
clasohm@0
  1499
  and conclusion B.  If eres_flg then checks 1st premise of rule also*)
clasohm@0
  1500
fun could_bires (Hs, B, eres_flg, rule) =
wenzelm@16847
  1501
    let fun could_reshyp (A1::_) = exists (fn H => could_unify (A1, H)) Hs
wenzelm@250
  1502
          | could_reshyp [] = false;  (*no premise -- illegal*)
wenzelm@250
  1503
    in  could_unify(concl_of rule, B) andalso
wenzelm@250
  1504
        (not eres_flg  orelse  could_reshyp (prems_of rule))
clasohm@0
  1505
    end;
clasohm@0
  1506
clasohm@0
  1507
(*Bi-resolution of a state with a list of (flag,rule) pairs.
clasohm@0
  1508
  Puts the rule above:  rule/state.  Renames vars in the rules. *)
wenzelm@250
  1509
fun biresolution match brules i state =
wenzelm@18035
  1510
    let val (stpairs, Bs, Bi, C) = dest_state(state,i);
wenzelm@18145
  1511
        val lift = lift_rule (cprem_of state i);
wenzelm@250
  1512
        val B = Logic.strip_assums_concl Bi;
wenzelm@250
  1513
        val Hs = Logic.strip_assums_hyp Bi;
wenzelm@18486
  1514
        val comp = bicompose_aux true match (state, (stpairs, Bs, Bi, C), true);
wenzelm@4270
  1515
        fun res [] = Seq.empty
wenzelm@250
  1516
          | res ((eres_flg, rule)::brules) =
nipkow@13642
  1517
              if !Pattern.trace_unify_fail orelse
nipkow@13642
  1518
                 could_bires (Hs, B, eres_flg, rule)
wenzelm@4270
  1519
              then Seq.make (*delay processing remainder till needed*)
skalberg@15531
  1520
                  (fn()=> SOME(comp (eres_flg, lift rule, nprems_of rule),
wenzelm@250
  1521
                               res brules))
wenzelm@250
  1522
              else res brules
wenzelm@4270
  1523
    in  Seq.flat (res brules)  end;
clasohm@0
  1524
clasohm@0
  1525
wenzelm@2509
  1526
(*** Oracles ***)
wenzelm@2509
  1527
wenzelm@16425
  1528
fun invoke_oracle_i thy1 name =
wenzelm@3812
  1529
  let
wenzelm@3812
  1530
    val oracle =
wenzelm@17412
  1531
      (case Symtab.lookup (#2 (#oracles (Theory.rep_theory thy1))) name of
skalberg@15531
  1532
        NONE => raise THM ("Unknown oracle: " ^ name, 0, [])
skalberg@15531
  1533
      | SOME (f, _) => f);
wenzelm@16847
  1534
    val thy_ref1 = Theory.self_ref thy1;
wenzelm@3812
  1535
  in
wenzelm@16425
  1536
    fn (thy2, data) =>
wenzelm@3812
  1537
      let
wenzelm@16847
  1538
        val thy' = Theory.merge (Theory.deref thy_ref1, thy2);
wenzelm@18969
  1539
        val (prop, T, maxidx) = Sign.certify_term thy' (oracle (thy', data));
wenzelm@3812
  1540
      in
wenzelm@3812
  1541
        if T <> propT then
wenzelm@3812
  1542
          raise THM ("Oracle's result must have type prop: " ^ name, 0, [])
wenzelm@16601
  1543
        else
wenzelm@16601
  1544
          Thm {thy_ref = Theory.self_ref thy',
berghofe@11518
  1545
            der = (true, Pt.oracle_proof name prop),
wenzelm@3812
  1546
            maxidx = maxidx,
wenzelm@16656
  1547
            shyps = may_insert_term_sorts thy' prop [],
wenzelm@16425
  1548
            hyps = [],
berghofe@13658
  1549
            tpairs = [],
wenzelm@16601
  1550
            prop = prop}
wenzelm@3812
  1551
      end
wenzelm@3812
  1552
  end;
wenzelm@3812
  1553
wenzelm@15672
  1554
fun invoke_oracle thy =
wenzelm@16425
  1555
  invoke_oracle_i thy o NameSpace.intern (Theory.oracle_space thy);
wenzelm@15672
  1556
clasohm@0
  1557
end;
paulson@1503
  1558
wenzelm@6089
  1559
structure BasicThm: BASIC_THM = Thm;
wenzelm@6089
  1560
open BasicThm;