(* Title: Pure/assumption.ML
Author: Makarius
Context assumptions, parameterized by export rules.
*)
signature ASSUMPTION =
sig
type export = bool -> cterm list -> (thm -> thm) * (term -> term)
val assume_export: export
val presume_export: export
val assume: cterm -> thm
val all_assms_of: Proof.context -> cterm list
val all_prems_of: Proof.context -> thm list
val extra_hyps: Proof.context -> thm -> term list
val local_assms_of: Proof.context -> Proof.context -> cterm list
val local_prems_of: Proof.context -> Proof.context -> thm list
val add_assms: export -> cterm list -> Proof.context -> thm list * Proof.context
val add_assumes: cterm list -> Proof.context -> thm list * Proof.context
val export: bool -> Proof.context -> Proof.context -> thm -> thm
val export_term: Proof.context -> Proof.context -> term -> term
val export_morphism: Proof.context -> Proof.context -> morphism
end;
structure Assumption: ASSUMPTION =
struct
(** basic rules **)
type export = bool -> cterm list -> (thm -> thm) * (term -> term);
(*
[A]
:
B
--------
#A ==> B
*)
fun assume_export is_goal asms =
(if is_goal then Drule.implies_intr_protected asms else Drule.implies_intr_list asms, fn t => t);
(*
[A]
:
B
-------
A ==> B
*)
fun presume_export _ = assume_export false;
val assume = MetaSimplifier.norm_hhf o Thm.assume;
(** local context data **)
datatype data = Data of
{assms: (export * cterm list) list, (*assumes: A ==> _*)
prems: thm list}; (*prems: A |- A*)
fun make_data (assms, prems) = Data {assms = assms, prems = prems};
structure Data = Proof_Data
(
type T = data;
fun init _ = make_data ([], []);
);
fun map_data f = Data.map (fn Data {assms, prems} => make_data (f (assms, prems)));
fun rep_data ctxt = Data.get ctxt |> (fn Data args => args);
(* all assumptions *)
val all_assumptions_of = #assms o rep_data;
val all_assms_of = maps #2 o all_assumptions_of;
val all_prems_of = #prems o rep_data;
fun extra_hyps ctxt th =
subtract (op aconv) (map Thm.term_of (all_assms_of ctxt)) (Thm.hyps_of th);
(*named prems -- legacy feature*)
val _ = Context.>>
(Context.map_theory (Global_Theory.add_thms_dynamic (Binding.name "prems",
fn Context.Theory _ => [] | Context.Proof ctxt => all_prems_of ctxt)));
(* local assumptions *)
fun local_assumptions_of inner outer =
drop (length (all_assumptions_of outer)) (all_assumptions_of inner);
val local_assms_of = maps #2 oo local_assumptions_of;
fun local_prems_of inner outer =
drop (length (all_prems_of outer)) (all_prems_of inner);
(* add assumptions *)
fun add_assms export new_asms =
let val new_prems = map assume new_asms in
map_data (fn (asms, prems) => (asms @ [(export, new_asms)], prems @ new_prems)) #>
pair new_prems
end;
val add_assumes = add_assms assume_export;
(* export *)
fun export is_goal inner outer =
MetaSimplifier.norm_hhf_protect #>
fold_rev (fn (e, As) => #1 (e is_goal As)) (local_assumptions_of inner outer) #>
MetaSimplifier.norm_hhf_protect;
fun export_term inner outer =
fold_rev (fn (e, As) => #2 (e false As)) (local_assumptions_of inner outer);
fun export_morphism inner outer =
let
val thm = export false inner outer;
val term = export_term inner outer;
val typ = Logic.type_map term;
in Morphism.morphism {binding = I, typ = typ, term = term, fact = map thm} end;
end;