Add UnfoldArg

2 files changed, 15 insertions, 0 deletions

diff --git a/src/Util/Tactics/ChangeInAll.v b/src/Util/Tactics/ChangeInAll.v
index 39a031207..c18055962 100644
--- a/src/Util/Tactics/ChangeInAll.v
+++ b/src/Util/Tactics/ChangeInAll.v
@@ -5,3 +5,7 @@ Ltac change_in_all from to :=
   repeat match goal with
          | [ H : _ |- _ ] => progress change from with to in H
          end.
+
+Ltac change_with_compute_in_all c :=
+  let c' := (eval compute in c) in
+  change c with c' in *.
diff --git a/src/Util/Tactics/UnfoldArg.v b/src/Util/Tactics/UnfoldArg.v
new file mode 100644
index 000000000..5f7772578
--- /dev/null
+++ b/src/Util/Tactics/UnfoldArg.v
@@ -0,0 +1,11 @@
+Require Import Crypto.Util.Tactics.ChangeInAll.
+
+(** fully reduces the first argument to [t], wherever it appears *)
+Ltac unfold_first_arg t :=
+  repeat match goal with
+         | [ H : context[t ?x] |- _ ] => progress change_with_compute_in_all x
+         | [ |- context[t ?x] ] => progress change_with_compute_in_all x
+         end.
+
+(* use uconstr so we can have underscores *)
+Tactic Notation "unfold_first_arg" uconstr(t) := unfold_first_arg t.