%------------------------------------------------------------------------------
% File     : Twee---2.4.2
% Problem  : SYN351+1 : TPTP v8.1.2. Released v2.0.0.
% 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 : n023.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 : Fri Sep  1 03:34:15 EDT 2023

% Result   : Theorem 0.21s 0.39s
% Output   : Proof 0.21s
% Verified : 
% SZS Type : -

% Comments : 
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%----WARNING: Could not form TPTP format derivation
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.04/0.13  % Problem  : SYN351+1 : TPTP v8.1.2. Released v2.0.0.
% 0.04/0.14  % Command  : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof
% 0.14/0.35  % Computer : n023.cluster.edu
% 0.14/0.35  % Model    : x86_64 x86_64
% 0.14/0.35  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.14/0.35  % Memory   : 8042.1875MB
% 0.14/0.35  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.14/0.35  % CPULimit : 300
% 0.14/0.35  % WCLimit  : 300
% 0.14/0.35  % DateTime : Sat Aug 26 21:35:56 EDT 2023
% 0.14/0.35  % CPUTime  : 
% 0.21/0.39  Command-line arguments: --no-flatten-goal
% 0.21/0.39  
% 0.21/0.39  % SZS status Theorem
% 0.21/0.39  
% 0.21/0.39  % SZS output start Proof
% 0.21/0.39  Take the following subset of the input axioms:
% 0.21/0.40    fof(church_46_18_3, conjecture, ![X1, X2]: ?[Y1, Y2]: ![Z]: (big_f(X1, Y2, X1, Z) => ((big_f(X1, Y1, X1, Y2) <=> big_f(Y1, X2, Y1, Y2)) => (big_f(X1, Y1, X1, Y2) => ((big_f(X1, Y2, Y1, Y2) => big_f(X1, Z, Y1, Z)) & (big_f(X1, Z, Y1, Z) => (big_f(X1, Y1, X1, Y2) <=> big_f(X1, Y2, Y1, Y2)))))))).
% 0.21/0.40  
% 0.21/0.40  Now clausify the problem and encode Horn clauses using encoding 3 of
% 0.21/0.40  http://www.cse.chalmers.se/~nicsma/papers/horn.pdf.
% 0.21/0.40  We repeatedly replace C & s=t => u=v by the two clauses:
% 0.21/0.40    fresh(y, y, x1...xn) = u
% 0.21/0.40    C => fresh(s, t, x1...xn) = v
% 0.21/0.40  where fresh is a fresh function symbol and x1..xn are the free
% 0.21/0.40  variables of u and v.
% 0.21/0.40  A predicate p(X) is encoded as p(X)=true (this is sound, because the
% 0.21/0.40  input problem has no model of domain size 1).
% 0.21/0.40  
% 0.21/0.40  The encoding turns the above axioms into the following unit equations and goals:
% 0.21/0.40  
% 0.21/0.40  Axiom 1 (church_46_18_3): big_f(x1, X, x1, Y) = true2.
% 0.21/0.40  
% 0.21/0.40  Goal 1 (church_46_18_3_6): tuple(big_f(x1, X, x1, Y), big_f(x1, Y, X, Y), big_f(x1, z(X, Y), X, z(X, Y))) = tuple(true2, true2, true2).
% 0.21/0.40  The goal is true when:
% 0.21/0.40    X = x1
% 0.21/0.40    Y = X
% 0.21/0.40  
% 0.21/0.40  Proof:
% 0.21/0.40    tuple(big_f(x1, x1, x1, X), big_f(x1, X, x1, X), big_f(x1, z(x1, X), x1, z(x1, X)))
% 0.21/0.40  = { by axiom 1 (church_46_18_3) }
% 0.21/0.40    tuple(true2, big_f(x1, X, x1, X), big_f(x1, z(x1, X), x1, z(x1, X)))
% 0.21/0.40  = { by axiom 1 (church_46_18_3) }
% 0.21/0.40    tuple(true2, true2, big_f(x1, z(x1, X), x1, z(x1, X)))
% 0.21/0.40  = { by axiom 1 (church_46_18_3) }
% 0.21/0.40    tuple(true2, true2, true2)
% 0.21/0.40  % SZS output end Proof
% 0.21/0.40  
% 0.21/0.40  RESULT: Theorem (the conjecture is true).
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