%------------------------------------------------------------------------------
% File : Z3---4.15.1
% Problem : SET074+1 : TPTP v9.0.0. Bugfixed v5.4.0.
% Transfm : none
% Format : tptp
% Command : run_E %s %d THM
% Computer : n006.cluster.edu
% Model : x86_64 x86_64
% CPU : Intel(R) Xeon(R) CPU E5-2620 v4 2.10GHz
% Memory : 8042.1875MB
% OS : Linux 3.10.0-693.el7.x86_64
% CPULimit : 300s
% WCLimit : 300s
% DateTime : Sat Jun 21 05:25:06 AM UTC 2025
% Result : Theorem 2.58s 2.79s
% Output : Proof 2.58s
% Verified :
% SZS Type : -
% Comments :
%------------------------------------------------------------------------------
%----WARNING: Could not form TPTP format derivation
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.03/0.12 % Problem : SET074+1 : TPTP v9.0.0. Bugfixed v5.4.0.
% 0.03/0.12 % Command : run_E %s %d THM
% 0.11/0.33 % Computer : n006.cluster.edu
% 0.11/0.33 % Model : x86_64 x86_64
% 0.11/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.11/0.33 % Memory : 8042.1875MB
% 0.11/0.33 % OS : Linux 3.10.0-693.el7.x86_64
% 0.11/0.33 % CPULimit : 300
% 0.11/0.33 % WCLimit : 300
% 0.11/0.33 % DateTime : Fri Jun 20 04:12:05 EDT 2025
% 0.11/0.33 % CPUTime :
% 2.58/2.79 % SZS status Theorem
% 2.58/2.79 % SZS output start Proof
% 2.58/2.79 tff(member_type, type, (
% 2.58/2.79 member: ( $i * $i ) > $o)).
% 2.58/2.79 tff(null_class_type, type, (
% 2.58/2.79 null_class: $i)).
% 2.58/2.79 tff(tptp_fun_Y_7_type, type, (
% 2.58/2.79 tptp_fun_Y_7: $i)).
% 2.58/2.79 tff(unordered_pair_type, type, (
% 2.58/2.79 unordered_pair: ( $i * $i ) > $i)).
% 2.58/2.79 tff(tptp_fun_X_8_type, type, (
% 2.58/2.79 tptp_fun_X_8: $i)).
% 2.58/2.79 tff(universal_class_type, type, (
% 2.58/2.79 universal_class: $i)).
% 2.58/2.79 tff(1,plain,
% 2.58/2.79 ((~![X: $i, Y: $i] : ((~member(Y, universal_class)) | (~(unordered_pair(X, Y) = null_class)))) <=> (~![X: $i, Y: $i] : ((~member(Y, universal_class)) | (~(unordered_pair(X, Y) = null_class))))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(2,plain,
% 2.58/2.79 ((~![X: $i, Y: $i] : (member(Y, universal_class) => (~(unordered_pair(X, Y) = null_class)))) <=> (~![X: $i, Y: $i] : ((~member(Y, universal_class)) | (~(unordered_pair(X, Y) = null_class))))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(3,axiom,(~![X: $i, Y: $i] : (member(Y, universal_class) => (~(unordered_pair(X, Y) = null_class)))), file('/export/starexec/sandbox2/benchmark/theBenchmark.p','corollary1_2')).
% 2.58/2.79 tff(4,plain,
% 2.58/2.79 (~![X: $i, Y: $i] : ((~member(Y, universal_class)) | (~(unordered_pair(X, Y) = null_class)))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[3, 2])).
% 2.58/2.79 tff(5,plain,
% 2.58/2.79 (~![X: $i, Y: $i] : ((~member(Y, universal_class)) | (~(unordered_pair(X, Y) = null_class)))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[4, 1])).
% 2.58/2.79 tff(6,plain,
% 2.58/2.79 (~![X: $i, Y: $i] : ((~member(Y, universal_class)) | (~(unordered_pair(X, Y) = null_class)))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[5, 1])).
% 2.58/2.79 tff(7,plain,
% 2.58/2.79 (~![X: $i, Y: $i] : ((~member(Y, universal_class)) | (~(unordered_pair(X, Y) = null_class)))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[6, 1])).
% 2.58/2.79 tff(8,plain,(
% 2.58/2.79 ~((~member(Y!7, universal_class)) | (~(unordered_pair(X!8, Y!7) = null_class)))),
% 2.58/2.79 inference(skolemize,[status(sab)],[7])).
% 2.58/2.79 tff(9,plain,
% 2.58/2.79 (unordered_pair(X!8, Y!7) = null_class),
% 2.58/2.79 inference(or_elim,[status(thm)],[8])).
% 2.58/2.79 tff(10,plain,
% 2.58/2.79 (member(Y!7, unordered_pair(X!8, Y!7)) <=> member(Y!7, null_class)),
% 2.58/2.79 inference(monotonicity,[status(thm)],[9])).
% 2.58/2.79 tff(11,plain,
% 2.58/2.79 (member(Y!7, null_class) <=> member(Y!7, unordered_pair(X!8, Y!7))),
% 2.58/2.79 inference(symmetry,[status(thm)],[10])).
% 2.58/2.79 tff(12,plain,
% 2.58/2.79 ((~member(Y!7, null_class)) <=> (~member(Y!7, unordered_pair(X!8, Y!7)))),
% 2.58/2.79 inference(monotonicity,[status(thm)],[11])).
% 2.58/2.79 tff(13,assumption,(~member(Y!7, null_class)), introduced(assumption)).
% 2.58/2.79 tff(14,plain,
% 2.58/2.79 (~member(Y!7, unordered_pair(X!8, Y!7))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[13, 12])).
% 2.58/2.79 tff(15,plain,
% 2.58/2.79 (^[U: $i, X: $i, Y: $i] : refl((~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y)))) <=> (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y)))))),
% 2.58/2.79 inference(bind,[status(th)],[])).
% 2.58/2.79 tff(16,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y)))) <=> ![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))),
% 2.58/2.79 inference(quant_intro,[status(thm)],[15])).
% 2.58/2.79 tff(17,plain,
% 2.58/2.79 (^[U: $i, X: $i, Y: $i] : trans(trans(monotonicity(rewrite((member(U, universal_class) & ((U = Y) | (U = X))) <=> (~((~member(U, universal_class)) | (~((U = Y) | (U = X)))))), ((member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X)))) <=> (member(U, unordered_pair(X, Y)) <=> (~((~member(U, universal_class)) | (~((U = Y) | (U = X)))))))), rewrite((member(U, unordered_pair(X, Y)) <=> (~((~member(U, universal_class)) | (~((U = Y) | (U = X)))))) <=> (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))), ((member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X)))) <=> (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y)))))), rewrite((~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y)))) <=> (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))), ((member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X)))) <=> (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))))),
% 2.58/2.79 inference(bind,[status(th)],[])).
% 2.58/2.79 tff(18,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X)))) <=> ![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))),
% 2.58/2.79 inference(quant_intro,[status(thm)],[17])).
% 2.58/2.79 tff(19,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X)))) <=> ![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X))))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(20,plain,
% 2.58/2.79 (^[U: $i, X: $i, Y: $i] : rewrite((member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = X) | (U = Y)))) <=> (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X)))))),
% 2.58/2.79 inference(bind,[status(th)],[])).
% 2.58/2.79 tff(21,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = X) | (U = Y)))) <=> ![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X))))),
% 2.58/2.79 inference(quant_intro,[status(thm)],[20])).
% 2.58/2.79 tff(22,axiom,(![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = X) | (U = Y))))), file('/export/starexec/sandbox2/benchmark/Axioms/SET005+0.ax','unordered_pair_defn')).
% 2.58/2.79 tff(23,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X))))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[22, 21])).
% 2.58/2.79 tff(24,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X))))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[23, 19])).
% 2.58/2.79 tff(25,plain,(
% 2.58/2.79 ![U: $i, X: $i, Y: $i] : (member(U, unordered_pair(X, Y)) <=> (member(U, universal_class) & ((U = Y) | (U = X))))),
% 2.58/2.79 inference(skolemize,[status(sab)],[24])).
% 2.58/2.79 tff(26,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[25, 18])).
% 2.58/2.79 tff(27,plain,
% 2.58/2.79 (![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[26, 16])).
% 2.58/2.79 tff(28,plain,
% 2.58/2.79 (((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))) <=> ((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(29,plain,
% 2.58/2.79 ((~(~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))) <=> (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(30,plain,
% 2.58/2.79 ((~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))) <=> (~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(31,plain,
% 2.58/2.79 (((~member(Y!7, universal_class)) <=> member(Y!7, unordered_pair(X!8, Y!7))) <=> (~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(32,plain,
% 2.58/2.79 (((~member(Y!7, universal_class)) | $false) <=> (~member(Y!7, universal_class))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(33,plain,
% 2.58/2.79 ((~$true) <=> $false),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(34,plain,
% 2.58/2.79 (($true | (Y!7 = X!8)) <=> $true),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(35,plain,
% 2.58/2.79 ((Y!7 = Y!7) <=> $true),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(36,plain,
% 2.58/2.79 (((Y!7 = Y!7) | (Y!7 = X!8)) <=> ($true | (Y!7 = X!8))),
% 2.58/2.79 inference(monotonicity,[status(thm)],[35])).
% 2.58/2.79 tff(37,plain,
% 2.58/2.79 (((Y!7 = Y!7) | (Y!7 = X!8)) <=> $true),
% 2.58/2.79 inference(transitivity,[status(thm)],[36, 34])).
% 2.58/2.79 tff(38,plain,
% 2.58/2.79 ((~((Y!7 = Y!7) | (Y!7 = X!8))) <=> (~$true)),
% 2.58/2.79 inference(monotonicity,[status(thm)],[37])).
% 2.58/2.79 tff(39,plain,
% 2.58/2.79 ((~((Y!7 = Y!7) | (Y!7 = X!8))) <=> $false),
% 2.58/2.79 inference(transitivity,[status(thm)],[38, 33])).
% 2.58/2.79 tff(40,plain,
% 2.58/2.79 (((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> ((~member(Y!7, universal_class)) | $false)),
% 2.58/2.79 inference(monotonicity,[status(thm)],[39])).
% 2.58/2.79 tff(41,plain,
% 2.58/2.79 (((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> (~member(Y!7, universal_class))),
% 2.58/2.79 inference(transitivity,[status(thm)],[40, 32])).
% 2.58/2.79 tff(42,plain,
% 2.58/2.79 ((((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7))) <=> ((~member(Y!7, universal_class)) <=> member(Y!7, unordered_pair(X!8, Y!7)))),
% 2.58/2.79 inference(monotonicity,[status(thm)],[41])).
% 2.58/2.79 tff(43,plain,
% 2.58/2.79 ((((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7))) <=> (~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(transitivity,[status(thm)],[42, 31])).
% 2.58/2.79 tff(44,plain,
% 2.58/2.79 ((((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7))) <=> (~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(transitivity,[status(thm)],[43, 30])).
% 2.58/2.79 tff(45,plain,
% 2.58/2.79 ((~(((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7)))) <=> (~(~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))))),
% 2.58/2.79 inference(monotonicity,[status(thm)],[44])).
% 2.58/2.79 tff(46,plain,
% 2.58/2.79 ((~(((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7)))) <=> (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))),
% 2.58/2.79 inference(transitivity,[status(thm)],[45, 29])).
% 2.58/2.79 tff(47,plain,
% 2.58/2.79 (((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (~(((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7))))) <=> ((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(monotonicity,[status(thm)],[46])).
% 2.58/2.79 tff(48,plain,
% 2.58/2.79 (((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (~(((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7))))) <=> ((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(transitivity,[status(thm)],[47, 28])).
% 2.58/2.79 tff(49,plain,
% 2.58/2.79 ((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (~(((~member(Y!7, universal_class)) | (~((Y!7 = Y!7) | (Y!7 = X!8)))) <=> member(Y!7, unordered_pair(X!8, Y!7))))),
% 2.58/2.79 inference(quant_inst,[status(thm)],[])).
% 2.58/2.79 tff(50,plain,
% 2.58/2.79 ((~![U: $i, X: $i, Y: $i] : (~(((~member(U, universal_class)) | (~((U = Y) | (U = X)))) <=> member(U, unordered_pair(X, Y))))) | (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[49, 48])).
% 2.58/2.79 tff(51,plain,
% 2.58/2.79 (member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7))),
% 2.58/2.79 inference(unit_resolution,[status(thm)],[50, 27])).
% 2.58/2.79 tff(52,plain,
% 2.58/2.79 (member(Y!7, universal_class)),
% 2.58/2.79 inference(or_elim,[status(thm)],[8])).
% 2.58/2.79 tff(53,plain,
% 2.58/2.79 ((~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))) | (~member(Y!7, universal_class)) | member(Y!7, unordered_pair(X!8, Y!7))),
% 2.58/2.79 inference(tautology,[status(thm)],[])).
% 2.58/2.79 tff(54,plain,
% 2.58/2.79 ((~(member(Y!7, universal_class) <=> member(Y!7, unordered_pair(X!8, Y!7)))) | member(Y!7, unordered_pair(X!8, Y!7))),
% 2.58/2.79 inference(unit_resolution,[status(thm)],[53, 52])).
% 2.58/2.79 tff(55,plain,
% 2.58/2.79 (member(Y!7, unordered_pair(X!8, Y!7))),
% 2.58/2.79 inference(unit_resolution,[status(thm)],[54, 51])).
% 2.58/2.79 tff(56,plain,
% 2.58/2.79 ($false),
% 2.58/2.79 inference(unit_resolution,[status(thm)],[55, 14])).
% 2.58/2.79 tff(57,plain,(member(Y!7, null_class)), inference(lemma,lemma(discharge,[]))).
% 2.58/2.79 tff(58,plain,
% 2.58/2.79 (^[X: $i] : refl((~member(X, null_class)) <=> (~member(X, null_class)))),
% 2.58/2.79 inference(bind,[status(th)],[])).
% 2.58/2.79 tff(59,plain,
% 2.58/2.79 (![X: $i] : (~member(X, null_class)) <=> ![X: $i] : (~member(X, null_class))),
% 2.58/2.79 inference(quant_intro,[status(thm)],[58])).
% 2.58/2.79 tff(60,plain,
% 2.58/2.79 (![X: $i] : (~member(X, null_class)) <=> ![X: $i] : (~member(X, null_class))),
% 2.58/2.79 inference(rewrite,[status(thm)],[])).
% 2.58/2.79 tff(61,axiom,(![X: $i] : (~member(X, null_class))), file('/export/starexec/sandbox2/benchmark/Axioms/SET005+0.ax','null_class_defn')).
% 2.58/2.79 tff(62,plain,
% 2.58/2.79 (![X: $i] : (~member(X, null_class))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[61, 60])).
% 2.58/2.79 tff(63,plain,(
% 2.58/2.79 ![X: $i] : (~member(X, null_class))),
% 2.58/2.79 inference(skolemize,[status(sab)],[62])).
% 2.58/2.79 tff(64,plain,
% 2.58/2.79 (![X: $i] : (~member(X, null_class))),
% 2.58/2.79 inference(modus_ponens,[status(thm)],[63, 59])).
% 2.58/2.79 tff(65,plain,
% 2.58/2.79 ((~![X: $i] : (~member(X, null_class))) | (~member(Y!7, null_class))),
% 2.58/2.79 inference(quant_inst,[status(thm)],[])).
% 2.58/2.79 tff(66,plain,
% 2.58/2.79 ($false),
% 2.58/2.79 inference(unit_resolution,[status(thm)],[65, 64, 57])).
% 2.58/2.79 % SZS output end Proof
% 2.58/2.80 % E exiting
%------------------------------------------------------------------------------