Add a tactic for field inequalities

Pair programming with Andres, a better proof of unifiedAddM1'_rep, some
progress on twistedAddAssoc.

1 files changed, 25 insertions, 0 deletions

diff --git a/src/Util/Tactics.v b/src/Util/Tactics.v
new file mode 100644
index 000000000..08ebfe13e
--- /dev/null
+++ b/src/Util/Tactics.v
@@ -0,0 +1,25 @@
+(** * Generic Tactics *)
+
+(* [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
+  match goal with
+  | [ H : T |- _ ] => fail 1
+  | _ => pose proof defn
+  end.
+(* [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) :=
+  match goal with
+  | [ H : T |- _ ] => fail 1
+  | _ => assert T
+  end.
+
+(* [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) :=
+  match goal with
+  | [ H : T |- _ ] => fail 1
+  | _ => assert T by tac
+  end.