0.06/0.12 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.06/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.13/0.33 % Computer : n023.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 : 180 0.13/0.33 % DateTime : Thu Aug 29 12:55:37 EDT 2019 0.13/0.33 % CPUTime : 1.82/1.99 % SZS status Unsatisfiable 1.82/1.99 1.82/1.99 % SZS output start Proof 1.82/1.99 Take the following subset of the input axioms: 1.82/1.99 fof(associativity, axiom, ![X, Y, Z]: multiply(multiply(X, Y), Z)=multiply(X, multiply(Y, Z))). 1.82/1.99 fof(left_identity, axiom, ![X]: X=multiply(identity, X)). 1.82/1.99 fof(left_inverse, axiom, ![X]: multiply(inverse(X), X)=identity). 1.82/1.99 fof(monotony_glb1, axiom, ![X, Y, Z]: multiply(X, greatest_lower_bound(Y, Z))=greatest_lower_bound(multiply(X, Y), multiply(X, Z))). 1.82/1.99 fof(monotony_glb2, axiom, ![X, Y, Z]: greatest_lower_bound(multiply(Y, X), multiply(Z, X))=multiply(greatest_lower_bound(Y, Z), X)). 1.82/1.99 fof(p12x_1, hypothesis, greatest_lower_bound(b, c)=greatest_lower_bound(a, c)). 1.82/1.99 fof(p12x_2, hypothesis, least_upper_bound(a, c)=least_upper_bound(b, c)). 1.82/1.99 fof(p12x_4, hypothesis, ![X, Y]: greatest_lower_bound(inverse(X), inverse(Y))=inverse(least_upper_bound(X, Y))). 1.82/1.99 fof(prove_p12x, negated_conjecture, a!=b). 1.82/1.99 fof(symmetry_of_glb, axiom, ![X, Y]: greatest_lower_bound(Y, X)=greatest_lower_bound(X, Y)). 1.82/1.99 fof(symmetry_of_lub, axiom, ![X, Y]: least_upper_bound(X, Y)=least_upper_bound(Y, X)). 1.82/1.99 1.82/1.99 Now clausify the problem and encode Horn clauses using encoding 3 of 1.82/1.99 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 1.82/1.99 We repeatedly replace C & s=t => u=v by the two clauses: 1.82/1.99 fresh(y, y, x1...xn) = u 1.82/1.99 C => fresh(s, t, x1...xn) = v 1.82/1.99 where fresh is a fresh function symbol and x1..xn are the free 1.82/1.99 variables of u and v. 1.82/1.99 A predicate p(X) is encoded as p(X)=true (this is sound, because the 1.82/1.99 input problem has no model of domain size 1). 1.82/1.99 1.82/1.99 The encoding turns the above axioms into the following unit equations and goals: 1.82/1.99 1.82/2.00 Axiom 1 (left_inverse): multiply(inverse(X), X) = identity. 1.82/2.00 Axiom 2 (associativity): multiply(multiply(X, Y), Z) = multiply(X, multiply(Y, Z)). 1.82/2.00 Axiom 3 (left_identity): X = multiply(identity, X). 1.82/2.00 Axiom 4 (symmetry_of_lub): least_upper_bound(X, Y) = least_upper_bound(Y, X). 1.82/2.00 Axiom 5 (monotony_glb1): multiply(X, greatest_lower_bound(Y, Z)) = greatest_lower_bound(multiply(X, Y), multiply(X, Z)). 1.82/2.00 Axiom 6 (symmetry_of_glb): greatest_lower_bound(X, Y) = greatest_lower_bound(Y, X). 1.82/2.00 Axiom 7 (monotony_glb2): greatest_lower_bound(multiply(X, Y), multiply(Z, Y)) = multiply(greatest_lower_bound(X, Z), Y). 1.82/2.00 Axiom 8 (p12x_4): greatest_lower_bound(inverse(X), inverse(Y)) = inverse(least_upper_bound(X, Y)). 1.82/2.00 Axiom 9 (p12x_1): greatest_lower_bound(b, c) = greatest_lower_bound(a, c). 1.82/2.00 Axiom 10 (p12x_2): least_upper_bound(a, c) = least_upper_bound(b, c). 1.82/2.00 1.82/2.00 Lemma 11: multiply(inverse(X), multiply(X, Y)) = Y. 1.82/2.00 Proof: 1.82/2.00 multiply(inverse(X), multiply(X, Y)) 1.82/2.00 = { by axiom 2 (associativity) } 1.82/2.00 multiply(multiply(inverse(X), X), Y) 1.82/2.00 = { by axiom 1 (left_inverse) } 1.82/2.00 multiply(identity, Y) 1.82/2.00 = { by axiom 3 (left_identity) } 1.82/2.00 Y 1.82/2.00 1.82/2.00 Lemma 12: multiply(inverse(inverse(X)), Y) = multiply(X, Y). 1.82/2.00 Proof: 1.82/2.00 multiply(inverse(inverse(X)), Y) 1.82/2.00 = { by lemma 11 } 1.82/2.00 multiply(inverse(inverse(X)), multiply(inverse(X), multiply(X, Y))) 1.82/2.00 = { by lemma 11 } 1.82/2.00 multiply(X, Y) 1.82/2.00 1.82/2.00 Lemma 13: multiply(inverse(inverse(X)), identity) = X. 1.82/2.00 Proof: 1.82/2.00 multiply(inverse(inverse(X)), identity) 1.82/2.00 = { by axiom 1 (left_inverse) } 1.82/2.00 multiply(inverse(inverse(X)), multiply(inverse(X), X)) 1.82/2.00 = { by lemma 11 } 1.82/2.00 X 1.82/2.00 1.82/2.00 Lemma 14: multiply(X, identity) = X. 1.82/2.00 Proof: 1.82/2.00 multiply(X, identity) 1.82/2.00 = { by lemma 12 } 1.82/2.00 multiply(inverse(inverse(X)), identity) 1.82/2.00 = { by lemma 13 } 1.82/2.00 X 1.82/2.00 1.82/2.00 Lemma 15: inverse(inverse(X)) = X. 1.82/2.00 Proof: 1.82/2.00 inverse(inverse(X)) 1.82/2.00 = { by lemma 14 } 1.82/2.00 multiply(inverse(inverse(X)), identity) 1.82/2.00 = { by lemma 13 } 1.82/2.00 X 1.82/2.00 1.82/2.00 Lemma 16: multiply(X, inverse(multiply(Y, X))) = inverse(Y). 1.82/2.00 Proof: 1.82/2.00 multiply(X, inverse(multiply(Y, X))) 1.82/2.00 = { by lemma 11 } 1.82/2.00 multiply(inverse(Y), multiply(Y, multiply(X, inverse(multiply(Y, X))))) 1.82/2.00 = { by axiom 2 (associativity) } 1.82/2.00 multiply(inverse(Y), multiply(multiply(Y, X), inverse(multiply(Y, X)))) 1.82/2.00 = { by lemma 12 } 1.82/2.00 multiply(inverse(Y), multiply(inverse(inverse(multiply(Y, X))), inverse(multiply(Y, X)))) 1.82/2.00 = { by axiom 1 (left_inverse) } 1.82/2.00 multiply(inverse(Y), identity) 1.82/2.00 = { by lemma 14 } 1.82/2.00 inverse(Y) 1.82/2.00 1.82/2.00 Lemma 17: multiply(inverse(least_upper_bound(Y, X)), Y) = multiply(inverse(X), greatest_lower_bound(Y, X)). 1.82/2.00 Proof: 1.82/2.00 multiply(inverse(least_upper_bound(Y, X)), Y) 1.82/2.00 = { by axiom 4 (symmetry_of_lub) } 1.82/2.00 multiply(inverse(least_upper_bound(X, Y)), Y) 1.82/2.00 = { by axiom 8 (p12x_4) } 1.82/2.00 multiply(greatest_lower_bound(inverse(X), inverse(Y)), Y) 1.82/2.00 = { by axiom 6 (symmetry_of_glb) } 1.82/2.00 multiply(greatest_lower_bound(inverse(Y), inverse(X)), Y) 1.82/2.00 = { by axiom 7 (monotony_glb2) } 1.82/2.00 greatest_lower_bound(multiply(inverse(Y), Y), multiply(inverse(X), Y)) 1.82/2.00 = { by axiom 1 (left_inverse) } 1.82/2.00 greatest_lower_bound(identity, multiply(inverse(X), Y)) 1.82/2.00 = { by axiom 1 (left_inverse) } 1.82/2.00 greatest_lower_bound(multiply(inverse(X), X), multiply(inverse(X), Y)) 1.82/2.00 = { by axiom 5 (monotony_glb1) } 1.82/2.00 multiply(inverse(X), greatest_lower_bound(X, Y)) 1.82/2.00 = { by axiom 6 (symmetry_of_glb) } 1.82/2.00 multiply(inverse(X), greatest_lower_bound(Y, X)) 1.82/2.00 1.82/2.00 Goal 1 (prove_p12x): a = b. 1.82/2.00 Proof: 1.82/2.00 a 1.82/2.00 = { by lemma 15 } 1.82/2.00 inverse(inverse(a)) 1.82/2.00 = { by lemma 16 } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(a), greatest_lower_bound(c, b)))) 1.82/2.00 = { by axiom 6 (symmetry_of_glb) } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(a), greatest_lower_bound(b, c)))) 1.82/2.00 = { by axiom 9 (p12x_1) } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(a), greatest_lower_bound(a, c)))) 1.82/2.00 = { by axiom 6 (symmetry_of_glb) } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(a), greatest_lower_bound(c, a)))) 1.82/2.00 = { by lemma 17 } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(least_upper_bound(c, a)), c))) 1.82/2.00 = { by axiom 4 (symmetry_of_lub) } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(least_upper_bound(a, c)), c))) 1.82/2.00 = { by axiom 10 (p12x_2) } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(least_upper_bound(b, c)), c))) 1.82/2.00 = { by axiom 4 (symmetry_of_lub) } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(least_upper_bound(c, b)), c))) 1.82/2.00 = { by lemma 17 } 1.82/2.00 multiply(greatest_lower_bound(c, b), inverse(multiply(inverse(b), greatest_lower_bound(c, b)))) 1.82/2.00 = { by lemma 16 } 1.82/2.00 inverse(inverse(b)) 1.82/2.00 = { by lemma 15 } 1.82/2.00 b 1.82/2.00 % SZS output end Proof 1.82/2.00 1.82/2.00 RESULT: Unsatisfiable (the axioms are contradictory). 1.82/2.00 EOF