TSTP Solution File: GRP076-1 by Twee---2.4.2

View Problem - Process Solution

%------------------------------------------------------------------------------
% File     : Twee---2.4.2
% Problem  : GRP076-1 : TPTP v8.1.2. Bugfixed v2.3.0.
% 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 : n019.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 01:16:53 EDT 2023

% Result   : Unsatisfiable 0.20s 0.41s
% Output   : Proof 0.20s
% Verified : 
% SZS Type : -

% Comments : 
%------------------------------------------------------------------------------
%----WARNING: Could not form TPTP format derivation
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.00/0.12  % Problem  : GRP076-1 : TPTP v8.1.2. Bugfixed v2.3.0.
% 0.00/0.13  % Command  : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof
% 0.16/0.34  % Computer : n019.cluster.edu
% 0.16/0.34  % Model    : x86_64 x86_64
% 0.16/0.34  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.16/0.34  % Memory   : 8042.1875MB
% 0.16/0.34  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.16/0.34  % CPULimit : 300
% 0.16/0.34  % WCLimit  : 300
% 0.16/0.34  % DateTime : Tue Aug 29 00:10:28 EDT 2023
% 0.20/0.34  % CPUTime  : 
% 0.20/0.41  Command-line arguments: --no-flatten-goal
% 0.20/0.41  
% 0.20/0.41  % SZS status Unsatisfiable
% 0.20/0.41  
% 0.20/0.45  % SZS output start Proof
% 0.20/0.45  Take the following subset of the input axioms:
% 0.20/0.45    fof(identity, axiom, ![X]: identity=double_divide(X, inverse(X))).
% 0.20/0.45    fof(inverse, axiom, ![X2]: inverse(X2)=double_divide(X2, identity)).
% 0.20/0.45    fof(multiply, axiom, ![Y, X2]: multiply(X2, Y)=double_divide(double_divide(Y, X2), identity)).
% 0.20/0.45    fof(prove_these_axioms, negated_conjecture, multiply(inverse(a1), a1)!=identity | (multiply(identity, a2)!=a2 | multiply(multiply(a3, b3), c3)!=multiply(a3, multiply(b3, c3)))).
% 0.20/0.45    fof(single_axiom, axiom, ![Z, X2, Y2]: double_divide(double_divide(X2, double_divide(double_divide(double_divide(X2, Y2), Z), double_divide(Y2, identity))), double_divide(identity, identity))=Z).
% 0.20/0.45  
% 0.20/0.45  Now clausify the problem and encode Horn clauses using encoding 3 of
% 0.20/0.45  http://www.cse.chalmers.se/~nicsma/papers/horn.pdf.
% 0.20/0.45  We repeatedly replace C & s=t => u=v by the two clauses:
% 0.20/0.45    fresh(y, y, x1...xn) = u
% 0.20/0.45    C => fresh(s, t, x1...xn) = v
% 0.20/0.45  where fresh is a fresh function symbol and x1..xn are the free
% 0.20/0.45  variables of u and v.
% 0.20/0.45  A predicate p(X) is encoded as p(X)=true (this is sound, because the
% 0.20/0.45  input problem has no model of domain size 1).
% 0.20/0.45  
% 0.20/0.45  The encoding turns the above axioms into the following unit equations and goals:
% 0.20/0.45  
% 0.20/0.45  Axiom 1 (inverse): inverse(X) = double_divide(X, identity).
% 0.20/0.45  Axiom 2 (identity): identity = double_divide(X, inverse(X)).
% 0.20/0.45  Axiom 3 (multiply): multiply(X, Y) = double_divide(double_divide(Y, X), identity).
% 0.20/0.45  Axiom 4 (single_axiom): double_divide(double_divide(X, double_divide(double_divide(double_divide(X, Y), Z), double_divide(Y, identity))), double_divide(identity, identity)) = Z.
% 0.20/0.45  
% 0.20/0.45  Lemma 5: double_divide(double_divide(X, double_divide(double_divide(double_divide(X, Y), Z), inverse(Y))), inverse(identity)) = Z.
% 0.20/0.45  Proof:
% 0.20/0.45    double_divide(double_divide(X, double_divide(double_divide(double_divide(X, Y), Z), inverse(Y))), inverse(identity))
% 0.20/0.45  = { by axiom 1 (inverse) }
% 0.20/0.45    double_divide(double_divide(X, double_divide(double_divide(double_divide(X, Y), Z), inverse(Y))), double_divide(identity, identity))
% 0.20/0.45  = { by axiom 1 (inverse) }
% 0.20/0.45    double_divide(double_divide(X, double_divide(double_divide(double_divide(X, Y), Z), double_divide(Y, identity))), double_divide(identity, identity))
% 0.20/0.45  = { by axiom 4 (single_axiom) }
% 0.20/0.45    Z
% 0.20/0.45  
% 0.20/0.45  Lemma 6: inverse(double_divide(X, Y)) = multiply(Y, X).
% 0.20/0.45  Proof:
% 0.20/0.45    inverse(double_divide(X, Y))
% 0.20/0.45  = { by axiom 1 (inverse) }
% 0.20/0.45    double_divide(double_divide(X, Y), identity)
% 0.20/0.45  = { by axiom 3 (multiply) R->L }
% 0.20/0.45    multiply(Y, X)
% 0.20/0.45  
% 0.20/0.45  Lemma 7: double_divide(double_divide(X, double_divide(identity, inverse(Y))), inverse(identity)) = multiply(Y, X).
% 0.20/0.45  Proof:
% 0.20/0.45    double_divide(double_divide(X, double_divide(identity, inverse(Y))), inverse(identity))
% 0.20/0.45  = { by axiom 2 (identity) }
% 0.20/0.45    double_divide(double_divide(X, double_divide(double_divide(double_divide(X, Y), inverse(double_divide(X, Y))), inverse(Y))), inverse(identity))
% 0.20/0.45  = { by lemma 5 }
% 0.20/0.45    inverse(double_divide(X, Y))
% 0.20/0.45  = { by lemma 6 }
% 0.20/0.45    multiply(Y, X)
% 0.20/0.45  
% 0.20/0.45  Lemma 8: double_divide(double_divide(double_divide(inverse(X), Y), Z), inverse(Y)) = double_divide(double_divide(X, Z), inverse(identity)).
% 0.20/0.45  Proof:
% 0.20/0.45    double_divide(double_divide(double_divide(inverse(X), Y), Z), inverse(Y))
% 0.20/0.45  = { by axiom 1 (inverse) }
% 0.20/0.45    double_divide(double_divide(double_divide(double_divide(X, identity), Y), Z), inverse(Y))
% 0.20/0.45  = { by lemma 5 R->L }
% 0.20/0.45    double_divide(double_divide(X, double_divide(double_divide(double_divide(X, identity), double_divide(double_divide(double_divide(double_divide(X, identity), Y), Z), inverse(Y))), inverse(identity))), inverse(identity))
% 0.20/0.45  = { by lemma 5 }
% 0.20/0.45    double_divide(double_divide(X, Z), inverse(identity))
% 0.20/0.45  
% 0.20/0.45  Lemma 9: multiply(X, inverse(inverse(Y))) = multiply(X, Y).
% 0.20/0.45  Proof:
% 0.20/0.45    multiply(X, inverse(inverse(Y)))
% 0.20/0.45  = { by axiom 1 (inverse) }
% 0.20/0.45    multiply(X, double_divide(inverse(Y), identity))
% 0.20/0.45  = { by lemma 7 R->L }
% 0.20/0.45    double_divide(double_divide(double_divide(inverse(Y), identity), double_divide(identity, inverse(X))), inverse(identity))
% 0.20/0.45  = { by lemma 8 }
% 0.20/0.45    double_divide(double_divide(Y, double_divide(identity, inverse(X))), inverse(identity))
% 0.20/0.45  = { by lemma 7 }
% 0.20/0.45    multiply(X, Y)
% 0.20/0.45  
% 0.20/0.45  Lemma 10: multiply(identity, X) = inverse(inverse(X)).
% 0.20/0.45  Proof:
% 0.20/0.45    multiply(identity, X)
% 0.20/0.45  = { by lemma 6 R->L }
% 0.20/0.45    inverse(double_divide(X, identity))
% 0.20/0.45  = { by axiom 1 (inverse) R->L }
% 0.20/0.45    inverse(inverse(X))
% 0.20/0.45  
% 0.20/0.45  Lemma 11: double_divide(inverse(X), inverse(identity)) = inverse(inverse(X)).
% 0.20/0.45  Proof:
% 0.20/0.45    double_divide(inverse(X), inverse(identity))
% 0.20/0.45  = { by axiom 1 (inverse) }
% 0.20/0.45    double_divide(double_divide(X, identity), inverse(identity))
% 0.20/0.45  = { by axiom 2 (identity) }
% 0.20/0.45    double_divide(double_divide(X, double_divide(identity, inverse(identity))), inverse(identity))
% 0.20/0.45  = { by lemma 7 }
% 0.20/0.45    multiply(identity, X)
% 0.20/0.45  = { by lemma 10 }
% 0.20/0.45    inverse(inverse(X))
% 0.20/0.45  
% 0.20/0.45  Lemma 12: inverse(inverse(inverse(inverse(X)))) = inverse(inverse(X)).
% 0.20/0.45  Proof:
% 0.20/0.45    inverse(inverse(inverse(inverse(X))))
% 0.20/0.45  = { by lemma 10 R->L }
% 0.20/0.45    multiply(identity, inverse(inverse(X)))
% 0.20/0.45  = { by lemma 9 }
% 0.20/0.45    multiply(identity, X)
% 0.20/0.45  = { by lemma 10 }
% 0.20/0.45    inverse(inverse(X))
% 0.20/0.45  
% 0.20/0.45  Lemma 13: multiply(inverse(identity), X) = inverse(inverse(X)).
% 0.20/0.45  Proof:
% 0.20/0.45    multiply(inverse(identity), X)
% 0.20/0.45  = { by lemma 9 R->L }
% 0.20/0.45    multiply(inverse(identity), inverse(inverse(X)))
% 0.20/0.45  = { by lemma 6 R->L }
% 0.20/0.45    inverse(double_divide(inverse(inverse(X)), inverse(identity)))
% 0.20/0.45  = { by lemma 11 }
% 0.20/0.46    inverse(inverse(inverse(inverse(X))))
% 0.20/0.46  = { by lemma 12 }
% 0.20/0.46    inverse(inverse(X))
% 0.20/0.46  
% 0.20/0.46  Lemma 14: multiply(inverse(X), X) = inverse(identity).
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(inverse(X), X)
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    inverse(double_divide(X, inverse(X)))
% 0.20/0.46  = { by axiom 2 (identity) R->L }
% 0.20/0.46    inverse(identity)
% 0.20/0.46  
% 0.20/0.46  Lemma 15: inverse(inverse(identity)) = inverse(identity).
% 0.20/0.46  Proof:
% 0.20/0.46    inverse(inverse(identity))
% 0.20/0.46  = { by lemma 13 R->L }
% 0.20/0.46    multiply(inverse(identity), identity)
% 0.20/0.46  = { by lemma 14 }
% 0.20/0.46    inverse(identity)
% 0.20/0.46  
% 0.20/0.46  Lemma 16: inverse(identity) = identity.
% 0.20/0.46  Proof:
% 0.20/0.46    inverse(identity)
% 0.20/0.46  = { by lemma 15 R->L }
% 0.20/0.46    inverse(inverse(identity))
% 0.20/0.46  = { by lemma 11 R->L }
% 0.20/0.46    double_divide(inverse(identity), inverse(identity))
% 0.20/0.46  = { by lemma 15 R->L }
% 0.20/0.46    double_divide(inverse(identity), inverse(inverse(identity)))
% 0.20/0.46  = { by axiom 2 (identity) R->L }
% 0.20/0.46    identity
% 0.20/0.46  
% 0.20/0.46  Lemma 17: multiply(multiply(X, inverse(Y)), Y) = X.
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(multiply(X, inverse(Y)), Y)
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    inverse(double_divide(Y, multiply(X, inverse(Y))))
% 0.20/0.46  = { by axiom 1 (inverse) }
% 0.20/0.46    double_divide(double_divide(Y, multiply(X, inverse(Y))), identity)
% 0.20/0.46  = { by lemma 16 R->L }
% 0.20/0.46    double_divide(double_divide(Y, multiply(X, inverse(Y))), inverse(identity))
% 0.20/0.46  = { by axiom 1 (inverse) }
% 0.20/0.46    double_divide(double_divide(Y, multiply(X, double_divide(Y, identity))), inverse(identity))
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    double_divide(double_divide(Y, inverse(double_divide(double_divide(Y, identity), X))), inverse(identity))
% 0.20/0.46  = { by axiom 1 (inverse) }
% 0.20/0.46    double_divide(double_divide(Y, double_divide(double_divide(double_divide(Y, identity), X), identity)), inverse(identity))
% 0.20/0.46  = { by lemma 16 R->L }
% 0.20/0.46    double_divide(double_divide(Y, double_divide(double_divide(double_divide(Y, identity), X), inverse(identity))), inverse(identity))
% 0.20/0.46  = { by lemma 5 }
% 0.20/0.46    X
% 0.20/0.46  
% 0.20/0.46  Lemma 18: multiply(X, inverse(multiply(Y, Z))) = multiply(X, double_divide(Z, Y)).
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(X, inverse(multiply(Y, Z)))
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    multiply(X, inverse(inverse(double_divide(Z, Y))))
% 0.20/0.46  = { by lemma 9 }
% 0.20/0.46    multiply(X, double_divide(Z, Y))
% 0.20/0.46  
% 0.20/0.46  Lemma 19: double_divide(multiply(X, Y), inverse(X)) = inverse(inverse(inverse(Y))).
% 0.20/0.46  Proof:
% 0.20/0.46    double_divide(multiply(X, Y), inverse(X))
% 0.20/0.46  = { by lemma 9 R->L }
% 0.20/0.46    double_divide(multiply(X, inverse(inverse(Y))), inverse(X))
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    double_divide(inverse(double_divide(inverse(inverse(Y)), X)), inverse(X))
% 0.20/0.46  = { by axiom 1 (inverse) }
% 0.20/0.46    double_divide(double_divide(double_divide(inverse(inverse(Y)), X), identity), inverse(X))
% 0.20/0.46  = { by lemma 8 }
% 0.20/0.46    double_divide(double_divide(inverse(Y), identity), inverse(identity))
% 0.20/0.46  = { by axiom 1 (inverse) R->L }
% 0.20/0.46    double_divide(inverse(inverse(Y)), inverse(identity))
% 0.20/0.46  = { by lemma 11 }
% 0.20/0.46    inverse(inverse(inverse(Y)))
% 0.20/0.46  
% 0.20/0.46  Lemma 20: multiply(inverse(X), multiply(X, Y)) = inverse(inverse(Y)).
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(inverse(X), multiply(X, Y))
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    inverse(double_divide(multiply(X, Y), inverse(X)))
% 0.20/0.46  = { by lemma 19 }
% 0.20/0.46    inverse(inverse(inverse(inverse(Y))))
% 0.20/0.46  = { by lemma 12 }
% 0.20/0.46    inverse(inverse(Y))
% 0.20/0.46  
% 0.20/0.46  Lemma 21: multiply(inverse(inverse(X)), Y) = inverse(inverse(multiply(X, Y))).
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(inverse(inverse(X)), Y)
% 0.20/0.46  = { by lemma 9 R->L }
% 0.20/0.46    multiply(inverse(inverse(X)), inverse(inverse(Y)))
% 0.20/0.46  = { by lemma 20 R->L }
% 0.20/0.46    multiply(inverse(inverse(X)), multiply(inverse(X), multiply(X, Y)))
% 0.20/0.46  = { by lemma 20 }
% 0.20/0.46    inverse(inverse(multiply(X, Y)))
% 0.20/0.46  
% 0.20/0.46  Lemma 22: inverse(inverse(multiply(X, identity))) = inverse(inverse(X)).
% 0.20/0.46  Proof:
% 0.20/0.46    inverse(inverse(multiply(X, identity)))
% 0.20/0.46  = { by lemma 21 R->L }
% 0.20/0.46    multiply(inverse(inverse(X)), identity)
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    inverse(double_divide(identity, inverse(inverse(X))))
% 0.20/0.46  = { by lemma 16 R->L }
% 0.20/0.46    inverse(double_divide(inverse(identity), inverse(inverse(X))))
% 0.20/0.46  = { by lemma 14 R->L }
% 0.20/0.46    inverse(double_divide(multiply(inverse(X), X), inverse(inverse(X))))
% 0.20/0.46  = { by lemma 19 }
% 0.20/0.46    inverse(inverse(inverse(inverse(X))))
% 0.20/0.46  = { by lemma 12 }
% 0.20/0.46    inverse(inverse(X))
% 0.20/0.46  
% 0.20/0.46  Lemma 23: multiply(X, double_divide(identity, Y)) = multiply(X, inverse(Y)).
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(X, double_divide(identity, Y))
% 0.20/0.46  = { by lemma 18 R->L }
% 0.20/0.46    multiply(X, inverse(multiply(Y, identity)))
% 0.20/0.46  = { by lemma 9 R->L }
% 0.20/0.46    multiply(X, inverse(inverse(inverse(multiply(Y, identity)))))
% 0.20/0.46  = { by lemma 22 }
% 0.20/0.46    multiply(X, inverse(inverse(inverse(Y))))
% 0.20/0.46  = { by lemma 9 }
% 0.20/0.46    multiply(X, inverse(Y))
% 0.20/0.46  
% 0.20/0.46  Lemma 24: multiply(identity, X) = X.
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(identity, X)
% 0.20/0.46  = { by lemma 16 R->L }
% 0.20/0.46    multiply(inverse(identity), X)
% 0.20/0.46  = { by lemma 14 R->L }
% 0.20/0.46    multiply(multiply(inverse(double_divide(identity, multiply(X, identity))), double_divide(identity, multiply(X, identity))), X)
% 0.20/0.46  = { by lemma 6 }
% 0.20/0.46    multiply(multiply(multiply(multiply(X, identity), identity), double_divide(identity, multiply(X, identity))), X)
% 0.20/0.46  = { by lemma 16 R->L }
% 0.20/0.46    multiply(multiply(multiply(multiply(X, inverse(identity)), identity), double_divide(identity, multiply(X, identity))), X)
% 0.20/0.46  = { by lemma 16 R->L }
% 0.20/0.46    multiply(multiply(multiply(multiply(X, inverse(identity)), inverse(identity)), double_divide(identity, multiply(X, identity))), X)
% 0.20/0.46  = { by lemma 15 R->L }
% 0.20/0.46    multiply(multiply(multiply(multiply(X, inverse(inverse(identity))), inverse(identity)), double_divide(identity, multiply(X, identity))), X)
% 0.20/0.46  = { by lemma 17 }
% 0.20/0.46    multiply(multiply(X, double_divide(identity, multiply(X, identity))), X)
% 0.20/0.46  = { by lemma 23 }
% 0.20/0.46    multiply(multiply(X, inverse(multiply(X, identity))), X)
% 0.20/0.46  = { by lemma 18 }
% 0.20/0.46    multiply(multiply(X, double_divide(identity, X)), X)
% 0.20/0.46  = { by lemma 23 }
% 0.20/0.46    multiply(multiply(X, inverse(X)), X)
% 0.20/0.46  = { by lemma 17 }
% 0.20/0.46    X
% 0.20/0.46  
% 0.20/0.46  Lemma 25: inverse(inverse(X)) = X.
% 0.20/0.46  Proof:
% 0.20/0.46    inverse(inverse(X))
% 0.20/0.46  = { by lemma 10 R->L }
% 0.20/0.46    multiply(identity, X)
% 0.20/0.46  = { by lemma 24 }
% 0.20/0.46    X
% 0.20/0.46  
% 0.20/0.46  Lemma 26: multiply(inverse(X), inverse(Y)) = double_divide(X, Y).
% 0.20/0.46  Proof:
% 0.20/0.46    multiply(inverse(X), inverse(Y))
% 0.20/0.46  = { by lemma 6 R->L }
% 0.20/0.46    inverse(double_divide(inverse(Y), inverse(X)))
% 0.20/0.46  = { by lemma 24 R->L }
% 0.20/0.46    inverse(double_divide(multiply(identity, inverse(Y)), inverse(X)))
% 0.20/0.47  = { by lemma 23 R->L }
% 0.20/0.47    inverse(double_divide(multiply(identity, double_divide(identity, Y)), inverse(X)))
% 0.20/0.47  = { by lemma 24 }
% 0.20/0.47    inverse(double_divide(double_divide(identity, Y), inverse(X)))
% 0.20/0.47  = { by axiom 2 (identity) }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(multiply(inverse(inverse(identity)), X)), inverse(inverse(multiply(inverse(inverse(identity)), X)))), Y), inverse(X)))
% 0.20/0.47  = { by lemma 25 }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(multiply(inverse(inverse(identity)), X)), multiply(inverse(inverse(identity)), X)), Y), inverse(X)))
% 0.20/0.47  = { by lemma 15 }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(multiply(inverse(identity), X)), multiply(inverse(inverse(identity)), X)), Y), inverse(X)))
% 0.20/0.47  = { by lemma 13 }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(inverse(inverse(X))), multiply(inverse(inverse(identity)), X)), Y), inverse(X)))
% 0.20/0.47  = { by lemma 25 }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(X), multiply(inverse(inverse(identity)), X)), Y), inverse(X)))
% 0.20/0.47  = { by lemma 21 }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(X), inverse(inverse(multiply(identity, X)))), Y), inverse(X)))
% 0.20/0.47  = { by lemma 25 }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(X), multiply(identity, X)), Y), inverse(X)))
% 0.20/0.47  = { by lemma 24 }
% 0.20/0.47    inverse(double_divide(double_divide(double_divide(inverse(X), X), Y), inverse(X)))
% 0.20/0.47  = { by lemma 8 }
% 0.20/0.47    inverse(double_divide(double_divide(X, Y), inverse(identity)))
% 0.20/0.47  = { by lemma 16 }
% 0.20/0.47    inverse(double_divide(double_divide(X, Y), identity))
% 0.20/0.47  = { by axiom 1 (inverse) R->L }
% 0.20/0.47    inverse(inverse(double_divide(X, Y)))
% 0.20/0.47  = { by lemma 25 }
% 0.20/0.47    double_divide(X, Y)
% 0.20/0.47  
% 0.20/0.47  Lemma 27: double_divide(X, inverse(Y)) = multiply(inverse(X), Y).
% 0.20/0.47  Proof:
% 0.20/0.47    double_divide(X, inverse(Y))
% 0.20/0.47  = { by lemma 26 R->L }
% 0.20/0.47    multiply(inverse(X), inverse(inverse(Y)))
% 0.20/0.47  = { by lemma 9 }
% 0.20/0.47    multiply(inverse(X), Y)
% 0.20/0.47  
% 0.20/0.47  Lemma 28: multiply(multiply(X, multiply(Y, inverse(Z))), Z) = multiply(X, Y).
% 0.20/0.47  Proof:
% 0.20/0.47    multiply(multiply(X, multiply(Y, inverse(Z))), Z)
% 0.20/0.47  = { by lemma 25 R->L }
% 0.20/0.47    multiply(multiply(X, inverse(inverse(multiply(Y, inverse(Z))))), Z)
% 0.20/0.47  = { by lemma 21 R->L }
% 0.20/0.47    multiply(multiply(X, multiply(inverse(inverse(Y)), inverse(Z))), Z)
% 0.20/0.47  = { by lemma 12 R->L }
% 0.20/0.47    multiply(multiply(X, multiply(inverse(inverse(inverse(inverse(Y)))), inverse(Z))), Z)
% 0.20/0.47  = { by lemma 26 }
% 0.20/0.47    multiply(multiply(X, double_divide(inverse(inverse(inverse(Y))), Z)), Z)
% 0.20/0.47  = { by lemma 25 }
% 0.20/0.47    multiply(multiply(X, double_divide(inverse(Y), Z)), Z)
% 0.20/0.47  = { by axiom 1 (inverse) }
% 0.20/0.47    multiply(multiply(X, double_divide(double_divide(Y, identity), Z)), Z)
% 0.20/0.47  = { by lemma 6 R->L }
% 0.20/0.47    multiply(inverse(double_divide(double_divide(double_divide(Y, identity), Z), X)), Z)
% 0.20/0.47  = { by lemma 27 R->L }
% 0.20/0.47    double_divide(double_divide(double_divide(double_divide(Y, identity), Z), X), inverse(Z))
% 0.20/0.47  = { by lemma 5 R->L }
% 0.20/0.47    double_divide(double_divide(Y, double_divide(double_divide(double_divide(Y, identity), double_divide(double_divide(double_divide(double_divide(Y, identity), Z), X), inverse(Z))), inverse(identity))), inverse(identity))
% 0.20/0.47  = { by lemma 5 }
% 0.20/0.47    double_divide(double_divide(Y, X), inverse(identity))
% 0.20/0.47  = { by lemma 27 }
% 0.20/0.47    multiply(inverse(double_divide(Y, X)), identity)
% 0.20/0.47  = { by lemma 25 R->L }
% 0.20/0.47    inverse(inverse(multiply(inverse(double_divide(Y, X)), identity)))
% 0.20/0.47  = { by lemma 22 }
% 0.20/0.47    inverse(inverse(inverse(double_divide(Y, X))))
% 0.20/0.47  = { by lemma 25 }
% 0.20/0.47    inverse(double_divide(Y, X))
% 0.20/0.47  = { by lemma 6 }
% 0.20/0.47    multiply(X, Y)
% 0.20/0.47  
% 0.20/0.47  Goal 1 (prove_these_axioms): tuple(multiply(inverse(a1), a1), multiply(identity, a2), multiply(multiply(a3, b3), c3)) = tuple(identity, a2, multiply(a3, multiply(b3, c3))).
% 0.20/0.47  Proof:
% 0.20/0.47    tuple(multiply(inverse(a1), a1), multiply(identity, a2), multiply(multiply(a3, b3), c3))
% 0.20/0.47  = { by lemma 10 }
% 0.20/0.47    tuple(multiply(inverse(a1), a1), inverse(inverse(a2)), multiply(multiply(a3, b3), c3))
% 0.20/0.47  = { by lemma 14 }
% 0.20/0.47    tuple(inverse(identity), inverse(inverse(a2)), multiply(multiply(a3, b3), c3))
% 0.20/0.47  = { by lemma 16 }
% 0.20/0.47    tuple(identity, inverse(inverse(a2)), multiply(multiply(a3, b3), c3))
% 0.20/0.47  = { by lemma 25 }
% 0.20/0.47    tuple(identity, a2, multiply(multiply(a3, b3), c3))
% 0.20/0.47  = { by lemma 25 R->L }
% 0.20/0.47    tuple(identity, a2, inverse(inverse(multiply(multiply(a3, b3), c3))))
% 0.20/0.47  = { by lemma 21 R->L }
% 0.20/0.47    tuple(identity, a2, multiply(inverse(inverse(multiply(a3, b3))), c3))
% 0.20/0.47  = { by lemma 10 R->L }
% 0.20/0.47    tuple(identity, a2, multiply(multiply(identity, multiply(a3, b3)), c3))
% 0.20/0.47  = { by lemma 28 R->L }
% 0.20/0.47    tuple(identity, a2, multiply(multiply(identity, multiply(multiply(a3, multiply(b3, inverse(inverse(c3)))), inverse(c3))), c3))
% 0.20/0.47  = { by lemma 28 }
% 0.20/0.47    tuple(identity, a2, multiply(identity, multiply(a3, multiply(b3, inverse(inverse(c3))))))
% 0.20/0.47  = { by lemma 9 }
% 0.20/0.47    tuple(identity, a2, multiply(identity, multiply(a3, multiply(b3, c3))))
% 0.20/0.47  = { by lemma 24 }
% 0.20/0.47    tuple(identity, a2, multiply(a3, multiply(b3, c3)))
% 0.20/0.47  % SZS output end Proof
% 0.20/0.47  
% 0.20/0.47  RESULT: Unsatisfiable (the axioms are contradictory).
%------------------------------------------------------------------------------