--- /dev/null
+
+include "logic/equality.ma".
+(* Inclusion of: SYN083-1.p *)
+(* -------------------------------------------------------------------------- *)
+(* File : SYN083-1 : TPTP v3.1.1. Released v1.0.0. *)
+(* Domain : Syntactic *)
+(* Problem : Pelletier Problem 61 *)
+(* Version : Especial. *)
+(* English : *)
+(* Refs : [Pel86] Pelletier (1986), Seventy-five Problems for Testing Au *)
+(* Source : [Pel86] *)
+(* Names : Pelletier 61 [Pel86] *)
+(* Status : Unsatisfiable *)
+(* Rating : 0.00 v2.0.0 *)
+(* Syntax : Number of clauses : 2 ( 0 non-Horn; 2 unit; 1 RR) *)
+(* Number of atoms : 2 ( 2 equality) *)
+(* Maximal clause size : 1 ( 1 average) *)
+(* Number of predicates : 1 ( 0 propositional; 2-2 arity) *)
+(* Number of functors : 5 ( 4 constant; 0-2 arity) *)
+(* Number of variables : 3 ( 0 singleton) *)
+(* Maximal term depth : 4 ( 4 average) *)
+(* Comments : *)
+(* -------------------------------------------------------------------------- *)
+theorem prove_this:
+ \forall Univ:Set.
+\forall a:Univ.
+\forall b:Univ.
+\forall c:Univ.
+\forall d:Univ.
+\forall f:\forall _:Univ.\forall _:Univ.Univ.
+\forall H0:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (f X (f Y Z)) (f (f X Y) Z).eq Univ (f a (f b (f c d))) (f (f (f a b) c) d)
+.
+intros.
+autobatch paramodulation timeout=100;
+try assumption.
+print proofterm.
+qed.
+(* -------------------------------------------------------------------------- *)