Library MetaRocq.Utils.MRTactics.UniquePose

From MetaRocq.Utils Require Import MRTactics.FindHyp.

pose proof defn, but only if no hypothesis of the same type exists. most useful for proofs of a proposition

Tactic Notation "unique" "pose" "proof" constr(defn) :=
  let T := type of defn in
  tryif let H := find_hyp T in fail 2 "Already a hypothesis" H "of type" T
  then fail
  else pose proof defn.

pose defn, but only if that hypothesis doesn't exist

Tactic Notation "unique" "pose" constr(defn) :=
  tryif let H := find_hyp_with_body defn in fail 2 "Already a hypothesis" H "with body" defn
  then fail
  else pose defn.

assert T, but only if no hypothesis of the same type exists. most useful for proofs of a proposition

Tactic Notation "unique" "assert" constr(T) :=
  tryif let H := find_hyp T in fail 2 "Already a hypothesis" H "of type" T
  then fail
  else assert T.

assert T, but only if no hypothesis of the same type exists. most useful for proofs of a proposition

Tactic Notation "unique" "assert" constr(T) "by" tactic3(tac) :=
  tryif let H := find_hyp T in fail 2 "Already a hypothesis" H "of type" T
  then fail
  else assert T by tac.