Fix bug #3732: firstorder was using detyping to build existential

instances and forgeting about the evars and universes that could appear
there... dirty hack gone, using the evar map properly and avoiding
needless constructions/deconstructions of terms.

1 files changed, 104 insertions, 0 deletions

diff --git a/test-suite/bugs/closed/3732.v b/test-suite/bugs/closed/3732.v
new file mode 100644
index 000000000..6e5952a52
--- /dev/null
+++ b/test-suite/bugs/closed/3732.v
@@ -0,0 +1,104 @@
+(* File reduced by coq-bug-finder from original input, then from 2073 lines to 358 lines, then from 359 lines to 218 lines, then from 107 lines to 92 lines *)
+(* coqc version trunk (October 2014) compiled on Oct 11 2014 1:13:41 with OCaml 4.01.0
+   coqtop version cagnode16:/afs/csail.mit.edu/u/j/jgross/coq-trunk,trunk (d65496f09c4b68fa318783e53f9cd6d5c18e1eb7) *)
+Require Coq.Lists.List.
+
+Import Coq.Lists.List.
+
+Set Implicit Arguments.
+Global Set Asymmetric Patterns.
+
+Section machine.
+  Variables pc state : Type.
+
+  Inductive propX (i := pc) (j := state) : list Type -> Type :=
+  | Inj : forall G, Prop -> propX G
+  | ExistsX : forall G A, propX (A :: G) -> propX G.
+
+  Implicit Arguments Inj [G].
+
+  Definition PropX := propX nil.
+  Fixpoint last (G : list Type) : Type.
+    exact (match G with
+             | nil => unit
+             | T :: nil => T
+             | _ :: G' => last G'
+           end).
+  Defined.
+  Fixpoint eatLast (G : list Type) : list Type.
+    exact (match G with
+             | nil => nil
+             | _ :: nil => nil
+             | x :: G' => x :: eatLast G'
+           end).
+  Defined.
+
+  Fixpoint subst G (p : propX G) : (last G -> PropX) -> propX (eatLast G) :=
+    match p with
+      | Inj _ P => fun _ => Inj P
+      | ExistsX G A p1 => fun p' =>
+                            match G return propX (A :: G) -> propX (eatLast (A :: G)) -> propX (eatLast G) with
+                              | nil => fun p1 _ => ExistsX p1
+                              | _ :: _ => fun _ rc => ExistsX rc
+                            end p1 (subst p1 (match G return (last G -> PropX) -> last (A :: G) -> PropX with
+                                                | nil => fun _ _ => Inj True
+                                                | _ => fun p' => p'
+                                              end p'))
+    end.
+
+  Definition spec := state -> PropX.
+  Definition codeSpec := pc -> option spec.
+
+  Inductive valid (specs : codeSpec) (G : list PropX) : PropX -> Prop := Env : forall P, In P G -> valid specs G P.
+  Definition interp specs := valid specs nil.
+End machine.
+Notation "'ExX' : A , P" := (ExistsX (A := A) P) (at level 89) : PropX_scope.
+Bind Scope PropX_scope with PropX propX.
+Variables pc state : Type.
+
+Inductive subs : list Type -> Type :=
+| SNil : subs nil
+| SCons : forall T Ts, (last (T :: Ts) -> PropX pc state) -> subs (eatLast (T :: Ts)) -> subs (T :: Ts).
+
+Fixpoint SPush G T (s : subs G) (f : T -> PropX pc state) : subs (T :: G) :=
+  match s in subs G return subs (T :: G) with
+    | SNil => SCons _ nil f SNil
+    | SCons T' Ts f' s' => SCons T (T' :: Ts) f' (SPush s' f)
+  end.
+
+Fixpoint Substs G (s : subs G) : propX pc state G -> PropX pc state :=
+  match s in subs G return propX pc state G -> PropX pc state with
+    | SNil => fun p => p
+    | SCons _ _ f s' => fun p => Substs s' (subst p f)
+  end.
+Variable specs : codeSpec pc state.
+
+Lemma simplify_fwd_ExistsX : forall G A s (p : propX pc state (A :: G)),
+                               interp specs (Substs s (ExX  : A, p))
+                               -> exists a, interp specs (Substs (SPush s a) p).
+admit.
+Defined.
+
+Goal    forall (G : list Type) (A : Type) (p : propX pc state (@cons Type A G))
+               (s : subs G)
+               (_ : @interp pc state specs (@Substs G s (@ExistsX pc state G A p)))
+               (P : forall _ : subs (@cons Type A G), Prop)
+               (_ : forall (s0 : subs (@cons Type A G))
+                           (_ : @interp pc state specs (@Substs (@cons Type A G) s0 p)),
+                      P s0),
+          @ex (forall _ : A, PropX pc state)
+              (fun a : forall _ : A, PropX pc state => P (@SPush G A s a)).
+  intros ? ? ? ? H ? H'.
+  apply simplify_fwd_ExistsX in H.
+  firstorder. 
+Qed.
+ (* Toplevel input, characters 15-19:
+Error: Illegal application:
+The term "cons" of type "forall A : Type, A -> list A -> list A"
+cannot be applied to the terms
+ "Type" : "Type"
+ "T" : "Type"
+ "G0" : "list Type"
+The 2nd term has type "Type@{Top.53}" which should be coercible to
+ "Type@{Top.12}".
+ *)
\ No newline at end of file