+include "logic/equality.ma".
+
+(* Inclusion of: BOO091-1.p *)
+
+(* -------------------------------------------------------------------------- *)
+
+(* File : BOO091-1 : TPTP v3.7.0. Released v2.6.0. *)
+
+(* Domain : Boolean Algebra *)
+
+(* Problem : Axiom C8 for Boolean algebra in the Sheffer stroke, part 1 *)
+
+(* Version : [EF+02] axioms. *)
+
+(* English : *)
+
+(* Refs : [EF+02] Ernst et al. (2002), More First-order Test Problems in *)
+
+(* : [MV+02] McCune et al. (2002), Short Single Axioms for Boolean *)
+
+(* Source : [TPTP] *)
+
+(* Names : *)
+
+(* Status : Unknown *)
+
+(* Rating : 1.00 v2.6.0 *)
+
+(* 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 : 3 ( 2 constant; 0-2 arity) *)
+
+(* Number of variables : 3 ( 1 singleton) *)
+
+(* Maximal term depth : 5 ( 2 average) *)
+
+(* Comments : A UEQ part of BOO047-1 *)
+
+(* -------------------------------------------------------------------------- *)
+ntheorem prove_meredith_2_basis_1:
+ (∀Univ:Type.∀A:Univ.∀B:Univ.∀C:Univ.
+∀a:Univ.
+∀b:Univ.
+∀nand:∀_:Univ.∀_:Univ.Univ.
+∀H0:∀A:Univ.∀B:Univ.∀C:Univ.eq Univ (nand (nand (nand A (nand A B)) A) (nand B (nand C A))) B.eq Univ (nand (nand a a) (nand b a)) a)
+.
+#Univ ##.
+#A ##.
+#B ##.
+#C ##.
+#a ##.
+#b ##.
+#nand ##.
+#H0 ##.
+nauto by H0 ##;
+ntry (nassumption) ##;
+nqed.
+
+(* -------------------------------------------------------------------------- *)