Commit 56a9fc6b authored by Michael Sammler's avatar Michael Sammler
Browse files

Add [learn_hyp_named] and [learn_hyp], fixes #73

parent 77cb2b8a
......@@ -254,19 +254,10 @@ Ltac multiset_instantiate :=
let e := fresh in evar (e:A);
let e' := eval unfold e in e in clear e;
lazymatch constr:(P e') with
| context [ {[ ?y ]} ] =>
(* Use [unless] to avoid creating a new hypothesis [H y : P y] if [P y]
already exists. *)
unify y e'; unless (P y) by assumption; pose proof (H y)
| context [ {[ ?y ]} ] => unify y e'; learn_hyp (H y)
end
| H : ( x : ?A, @?P x), _ : context [multiplicity ?y _] |- _ =>
(* Use [unless] to avoid creating a new hypothesis [H y : P y] if [P y]
already exists. *)
unless (P y) by assumption; pose proof (H y)
| H : ( x : ?A, @?P x) |- context [multiplicity ?y _] =>
(* Use [unless] to avoid creating a new hypothesis [H y : P y] if [P y]
already exists. *)
unless (P y) by assumption; pose proof (H y)
| H : ( x : ?A, _), _ : context [multiplicity ?y _] |- _ => learn_hyp (H y)
| H : ( x : ?A, _) |- context [multiplicity ?y _] => learn_hyp (H y)
end.
(** Step 4: simplify singletons *)
......
......@@ -525,6 +525,18 @@ Definition block {A : Type} (a : A) := a.
Ltac block_goal := match goal with [ |- ?T ] => change (block T) end.
Ltac unblock_goal := unfold block in *.
(** [learn_hyp p as H] and [learn_hyp p], where [p] is a proof of [P],
add [P] to the context and fail if [P] already exists in the context.
This is a simple form of the learning pattern. These tactics are
inspired by [Program.Tactics.add_hypothesis]. *)
Tactic Notation "learn_hyp" constr(p) "as" ident(H') :=
let P := type of p in
match goal with
| H : P |- _ => fail 1
| _ => pose proof p as H'
end.
Tactic Notation "learn_hyp" constr(p) :=
let H := fresh in learn_hyp p as H.
(** The tactic [select pat tac] finds the last (i.e., bottommost) hypothesis
matching [pat] and passes it to the continuation [tac]. Its main advantage over
......
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