TSTP Solution File: LCL164-1 by Twee---2.4.2

View Problem - Process Solution

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% File     : Twee---2.4.2
% Problem  : LCL164-1 : TPTP v8.1.2. Released v1.0.0.
% Transfm  : none
% Format   : tptp:raw
% Command  : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof

% Computer : n025.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 : Thu Aug 31 08:17:43 EDT 2023

% Result   : Unsatisfiable 0.20s 0.38s
% Output   : Proof 0.20s
% Verified : 
% SZS Type : -

% Comments : 
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%----WARNING: Could not form TPTP format derivation
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%----ORIGINAL SYSTEM OUTPUT
% 0.00/0.12  % Problem  : LCL164-1 : TPTP v8.1.2. Released v1.0.0.
% 0.00/0.13  % Command  : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof
% 0.13/0.33  % Computer : n025.cluster.edu
% 0.13/0.33  % Model    : x86_64 x86_64
% 0.13/0.33  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.13/0.33  % Memory   : 8042.1875MB
% 0.13/0.33  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.13/0.33  % CPULimit : 300
% 0.13/0.33  % WCLimit  : 300
% 0.13/0.33  % DateTime : Thu Aug 24 20:44:36 EDT 2023
% 0.13/0.34  % CPUTime  : 
% 0.20/0.38  Command-line arguments: --set-join --lhs-weight 1 --no-flatten-goal --complete-subsets --goal-heuristic
% 0.20/0.38  
% 0.20/0.38  % SZS status Unsatisfiable
% 0.20/0.38  
% 0.20/0.38  % SZS output start Proof
% 0.20/0.38  Axiom 1 (and_star_commutativity): and_star(X, Y) = and_star(Y, X).
% 0.20/0.38  Axiom 2 (axiom_3): xor(X, X) = falsehood.
% 0.20/0.38  Axiom 3 (xor_commutativity): xor(X, Y) = xor(Y, X).
% 0.20/0.38  Axiom 4 (axiom_2): xor(X, falsehood) = X.
% 0.20/0.39  Axiom 5 (axiom_1): not(X) = xor(X, truth).
% 0.20/0.39  Axiom 6 (axiom_6): and_star(xor(truth, X), X) = falsehood.
% 0.20/0.39  Axiom 7 (axiom_7): xor(X, xor(truth, Y)) = xor(xor(X, truth), Y).
% 0.20/0.39  Axiom 8 (implies_definition): implies(X, Y) = xor(truth, and_star(X, xor(truth, Y))).
% 0.20/0.39  
% 0.20/0.39  Lemma 9: xor(truth, X) = not(X).
% 0.20/0.39  Proof:
% 0.20/0.39    xor(truth, X)
% 0.20/0.39  = { by axiom 3 (xor_commutativity) R->L }
% 0.20/0.39    xor(X, truth)
% 0.20/0.39  = { by axiom 5 (axiom_1) R->L }
% 0.20/0.39    not(X)
% 0.20/0.39  
% 0.20/0.39  Lemma 10: not(and_star(X, not(Y))) = implies(X, Y).
% 0.20/0.39  Proof:
% 0.20/0.39    not(and_star(X, not(Y)))
% 0.20/0.39  = { by lemma 9 R->L }
% 0.20/0.39    not(and_star(X, xor(truth, Y)))
% 0.20/0.39  = { by lemma 9 R->L }
% 0.20/0.39    xor(truth, and_star(X, xor(truth, Y)))
% 0.20/0.39  = { by axiom 8 (implies_definition) R->L }
% 0.20/0.39    implies(X, Y)
% 0.20/0.39  
% 0.20/0.39  Goal 1 (prove_wajsberg_axiom): implies(implies(not(x), not(y)), implies(y, x)) = truth.
% 0.20/0.39  Proof:
% 0.20/0.39    implies(implies(not(x), not(y)), implies(y, x))
% 0.20/0.39  = { by lemma 10 R->L }
% 0.20/0.39    implies(not(and_star(not(x), not(not(y)))), implies(y, x))
% 0.20/0.39  = { by axiom 1 (and_star_commutativity) }
% 0.20/0.39    implies(not(and_star(not(not(y)), not(x))), implies(y, x))
% 0.20/0.39  = { by lemma 10 }
% 0.20/0.39    implies(implies(not(not(y)), x), implies(y, x))
% 0.20/0.39  = { by axiom 5 (axiom_1) }
% 0.20/0.39    implies(implies(xor(not(y), truth), x), implies(y, x))
% 0.20/0.39  = { by axiom 5 (axiom_1) }
% 0.20/0.39    implies(implies(xor(xor(y, truth), truth), x), implies(y, x))
% 0.20/0.39  = { by axiom 7 (axiom_7) R->L }
% 0.20/0.39    implies(implies(xor(y, xor(truth, truth)), x), implies(y, x))
% 0.20/0.39  = { by axiom 2 (axiom_3) }
% 0.20/0.39    implies(implies(xor(y, falsehood), x), implies(y, x))
% 0.20/0.39  = { by axiom 4 (axiom_2) }
% 0.20/0.39    implies(implies(y, x), implies(y, x))
% 0.20/0.39  = { by axiom 8 (implies_definition) }
% 0.20/0.39    xor(truth, and_star(implies(y, x), xor(truth, implies(y, x))))
% 0.20/0.39  = { by axiom 1 (and_star_commutativity) R->L }
% 0.20/0.39    xor(truth, and_star(xor(truth, implies(y, x)), implies(y, x)))
% 0.20/0.39  = { by axiom 6 (axiom_6) }
% 0.20/0.39    xor(truth, falsehood)
% 0.20/0.39  = { by axiom 4 (axiom_2) }
% 0.20/0.39    truth
% 0.20/0.39  % SZS output end Proof
% 0.20/0.39  
% 0.20/0.39  RESULT: Unsatisfiable (the axioms are contradictory).
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