Goal Prop.

pose (P:=(fun x y :Prop => y)).
evar (Q: (forall X Y,P X Y -> Prop)) .

instantiate (1:= fun _ => _ ) in (Value of Q).
instantiate (1:= fun _ => _ ) in (Value of Q).
instantiate (1:= fun _ => _ ) in (Value of Q).

instantiate (1:=H) in (Value  of Q).

Admitted.