Merge PR #6555: Use let-in aware prod_applist_assum in dtauto and firstorder.

1 files changed, 24 insertions, 0 deletions

diff --git a/test-suite/success/dtauto-let-deps.v b/test-suite/success/dtauto-let-deps.v
new file mode 100644
index 000000000..094b2f8b3
--- /dev/null
+++ b/test-suite/success/dtauto-let-deps.v
@@ -0,0 +1,24 @@
+(*
+This test is sensitive to changes in which let-ins are expanded when checking
+for dependencies in constructors.
+If the (x := X) is not reduced, Foo1 won't be recognized as a conjunction,
+and if the (y := X) is reduced, Foo2 will be recognized as a conjunction.
+
+This tests the behavior of engine/termops.ml : prod_applist_assum,
+which is currently specified to reduce exactly the parameters.
+
+If dtauto is changed to reduce lets in constructors before checking dependency,
+this test will need to be changed.
+*)
+
+Context (P Q : Type).
+Inductive Foo1 (X : Type) (x := X) := foo1 : let y := X in P -> Q -> Foo1 x.
+Inductive Foo2 (X : Type) (x := X) := foo2 : let y := X in P -> Q -> Foo2 y.
+
+Goal P -> Q -> Foo1 nat.
+solve [dtauto].
+Qed.
+
+Goal P -> Q -> Foo2 nat.
+Fail solve [dtauto].
+Abort.