0.07/0.13 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.07/0.14 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.14/0.35 % Computer : n008.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 : 180 0.14/0.35 % DateTime : Thu Aug 29 12:05:23 EDT 2019 0.14/0.35 % CPUTime : 0.85/1.03 % SZS status Unsatisfiable 0.85/1.03 0.85/1.03 % SZS output start Proof 0.85/1.03 Take the following subset of the input axioms: 1.09/1.28 fof(associativity, axiom, ![Y, Z, X]: multiply(multiply(X, Y), Z)=multiply(X, multiply(Y, Z))). 1.09/1.28 fof(intersection_associative, axiom, ![Y, Z, X]: intersection(intersection(X, Y), Z)=intersection(X, intersection(Y, Z))). 1.09/1.28 fof(intersection_commutative, axiom, ![Y, X]: intersection(Y, X)=intersection(X, Y)). 1.09/1.28 fof(intersection_union_absorbtion, axiom, ![Y, X]: Y=intersection(union(X, Y), Y)). 1.09/1.28 fof(inverse_involution, axiom, ![X]: inverse(inverse(X))=X). 1.09/1.28 fof(inverse_of_identity, axiom, identity=inverse(identity)). 1.09/1.28 fof(inverse_product_lemma, axiom, ![Y, X]: inverse(multiply(X, Y))=multiply(inverse(Y), inverse(X))). 1.09/1.28 fof(left_identity, axiom, ![X]: X=multiply(identity, X)). 1.09/1.28 fof(left_inverse, axiom, ![X]: multiply(inverse(X), X)=identity). 1.09/1.28 fof(multiply_intersection1, axiom, ![Y, Z, X]: multiply(X, intersection(Y, Z))=intersection(multiply(X, Y), multiply(X, Z))). 1.09/1.28 fof(multiply_intersection2, axiom, ![Y, Z, X]: intersection(multiply(Y, X), multiply(Z, X))=multiply(intersection(Y, Z), X)). 1.09/1.28 fof(multiply_union1, axiom, ![Y, Z, X]: union(multiply(X, Y), multiply(X, Z))=multiply(X, union(Y, Z))). 1.09/1.28 fof(multiply_union2, axiom, ![Y, Z, X]: multiply(union(Y, Z), X)=union(multiply(Y, X), multiply(Z, X))). 1.09/1.28 fof(negative_part, axiom, ![X]: intersection(X, identity)=negative_part(X)). 1.09/1.28 fof(positive_part, axiom, ![X]: union(X, identity)=positive_part(X)). 1.09/1.28 fof(prove_product, negated_conjecture, a!=multiply(positive_part(a), negative_part(a))). 1.09/1.28 fof(union_associative, axiom, ![Y, Z, X]: union(union(X, Y), Z)=union(X, union(Y, Z))). 1.09/1.28 fof(union_commutative, axiom, ![Y, X]: union(X, Y)=union(Y, X)). 1.09/1.28 fof(union_intersection_absorbtion, axiom, ![Y, X]: Y=union(intersection(X, Y), Y)). 1.09/1.28 1.09/1.28 Now clausify the problem and encode Horn clauses using encoding 3 of 1.09/1.28 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 1.09/1.28 We repeatedly replace C & s=t => u=v by the two clauses: 1.09/1.28 fresh(y, y, x1...xn) = u 1.09/1.28 C => fresh(s, t, x1...xn) = v 1.09/1.28 where fresh is a fresh function symbol and x1..xn are the free 1.09/1.28 variables of u and v. 1.09/1.28 A predicate p(X) is encoded as p(X)=true (this is sound, because the 1.09/1.28 input problem has no model of domain size 1). 1.09/1.28 1.09/1.28 The encoding turns the above axioms into the following unit equations and goals: 1.09/1.28 1.09/1.28 Axiom 1 (left_inverse): multiply(inverse(X), X) = identity. 1.09/1.28 Axiom 2 (associativity): multiply(multiply(X, Y), Z) = multiply(X, multiply(Y, Z)). 1.09/1.28 Axiom 3 (left_identity): X = multiply(identity, X). 1.09/1.28 Axiom 4 (intersection_commutative): intersection(X, Y) = intersection(Y, X). 1.09/1.28 Axiom 5 (union_commutative): union(X, Y) = union(Y, X). 1.09/1.28 Axiom 6 (intersection_union_absorbtion): X = intersection(union(Y, X), X). 1.09/1.28 Axiom 7 (inverse_involution): inverse(inverse(X)) = X. 1.09/1.28 Axiom 8 (inverse_product_lemma): inverse(multiply(X, Y)) = multiply(inverse(Y), inverse(X)). 1.09/1.28 Axiom 9 (multiply_union1): union(multiply(X, Y), multiply(X, Z)) = multiply(X, union(Y, Z)). 1.09/1.28 Axiom 10 (intersection_associative): intersection(intersection(X, Y), Z) = intersection(X, intersection(Y, Z)). 1.09/1.28 Axiom 11 (multiply_intersection1): multiply(X, intersection(Y, Z)) = intersection(multiply(X, Y), multiply(X, Z)). 1.09/1.28 Axiom 12 (multiply_intersection2): intersection(multiply(X, Y), multiply(Z, Y)) = multiply(intersection(X, Z), Y). 1.09/1.28 Axiom 13 (positive_part): union(X, identity) = positive_part(X). 1.09/1.28 Axiom 14 (union_associative): union(union(X, Y), Z) = union(X, union(Y, Z)). 1.09/1.28 Axiom 15 (negative_part): intersection(X, identity) = negative_part(X). 1.09/1.28 Axiom 16 (inverse_of_identity): identity = inverse(identity). 1.09/1.28 Axiom 17 (union_intersection_absorbtion): X = union(intersection(Y, X), X). 1.09/1.28 Axiom 18 (multiply_union2): multiply(union(X, Y), Z) = union(multiply(X, Z), multiply(Y, Z)). 1.09/1.28 1.09/1.28 Lemma 19: multiply(inverse(X), multiply(X, Y)) = Y. 1.09/1.28 Proof: 1.09/1.28 multiply(inverse(X), multiply(X, Y)) 1.09/1.28 = { by axiom 2 (associativity) } 1.09/1.28 multiply(multiply(inverse(X), X), Y) 1.09/1.28 = { by axiom 1 (left_inverse) } 1.09/1.28 multiply(identity, Y) 1.09/1.28 = { by axiom 3 (left_identity) } 1.09/1.28 Y 1.09/1.28 1.09/1.28 Lemma 20: union(Y, multiply(X, Y)) = multiply(positive_part(X), Y). 1.09/1.28 Proof: 1.09/1.28 union(Y, multiply(X, Y)) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(multiply(X, Y), Y) 1.09/1.28 = { by axiom 3 (left_identity) } 1.09/1.28 union(multiply(X, Y), multiply(identity, Y)) 1.09/1.28 = { by axiom 18 (multiply_union2) } 1.09/1.28 multiply(union(X, identity), Y) 1.09/1.28 = { by axiom 13 (positive_part) } 1.09/1.28 multiply(positive_part(X), Y) 1.09/1.28 1.09/1.28 Lemma 21: intersection(identity, X) = negative_part(X). 1.09/1.28 Proof: 1.09/1.28 intersection(identity, X) 1.09/1.28 = { by axiom 4 (intersection_commutative) } 1.09/1.28 intersection(X, identity) 1.09/1.28 = { by axiom 15 (negative_part) } 1.09/1.28 negative_part(X) 1.09/1.28 1.09/1.28 Lemma 22: multiply(inverse(X), intersection(X, Y)) = negative_part(multiply(inverse(X), Y)). 1.09/1.28 Proof: 1.09/1.28 multiply(inverse(X), intersection(X, Y)) 1.09/1.28 = { by axiom 11 (multiply_intersection1) } 1.09/1.28 intersection(multiply(inverse(X), X), multiply(inverse(X), Y)) 1.09/1.28 = { by axiom 1 (left_inverse) } 1.09/1.28 intersection(identity, multiply(inverse(X), Y)) 1.09/1.28 = { by lemma 21 } 1.09/1.28 negative_part(multiply(inverse(X), Y)) 1.09/1.28 1.09/1.28 Lemma 23: multiply(X, identity) = X. 1.09/1.28 Proof: 1.09/1.28 multiply(X, identity) 1.09/1.28 = { by axiom 7 (inverse_involution) } 1.09/1.28 inverse(inverse(multiply(X, identity))) 1.09/1.28 = { by axiom 8 (inverse_product_lemma) } 1.09/1.28 inverse(multiply(inverse(identity), inverse(X))) 1.09/1.28 = { by axiom 16 (inverse_of_identity) } 1.09/1.28 inverse(multiply(identity, inverse(X))) 1.09/1.28 = { by axiom 3 (left_identity) } 1.09/1.28 inverse(inverse(X)) 1.09/1.28 = { by axiom 7 (inverse_involution) } 1.09/1.28 X 1.09/1.28 1.09/1.28 Lemma 24: multiply(inverse(X), negative_part(X)) = negative_part(inverse(X)). 1.09/1.28 Proof: 1.09/1.28 multiply(inverse(X), negative_part(X)) 1.09/1.28 = { by axiom 15 (negative_part) } 1.09/1.28 multiply(inverse(X), intersection(X, identity)) 1.09/1.28 = { by lemma 22 } 1.09/1.28 negative_part(multiply(inverse(X), identity)) 1.09/1.28 = { by lemma 23 } 1.09/1.28 negative_part(inverse(X)) 1.09/1.28 1.09/1.28 Lemma 25: multiply(positive_part(inverse(X)), negative_part(X)) = multiply(positive_part(X), negative_part(inverse(X))). 1.09/1.28 Proof: 1.09/1.28 multiply(positive_part(inverse(X)), negative_part(X)) 1.09/1.28 = { by lemma 20 } 1.09/1.28 union(negative_part(X), multiply(inverse(X), negative_part(X))) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(multiply(inverse(X), negative_part(X)), negative_part(X)) 1.09/1.28 = { by lemma 19 } 1.09/1.28 union(multiply(inverse(X), negative_part(X)), multiply(inverse(inverse(X)), multiply(inverse(X), negative_part(X)))) 1.09/1.28 = { by lemma 20 } 1.09/1.28 multiply(positive_part(inverse(inverse(X))), multiply(inverse(X), negative_part(X))) 1.09/1.28 = { by axiom 7 (inverse_involution) } 1.09/1.28 multiply(positive_part(X), multiply(inverse(X), negative_part(X))) 1.09/1.28 = { by lemma 24 } 1.09/1.28 multiply(positive_part(X), negative_part(inverse(X))) 1.09/1.28 1.09/1.28 Lemma 26: intersection(Y, multiply(X, Y)) = multiply(negative_part(X), Y). 1.09/1.28 Proof: 1.09/1.28 intersection(Y, multiply(X, Y)) 1.09/1.28 = { by axiom 3 (left_identity) } 1.09/1.28 intersection(multiply(identity, Y), multiply(X, Y)) 1.09/1.28 = { by axiom 12 (multiply_intersection2) } 1.09/1.28 multiply(intersection(identity, X), Y) 1.09/1.28 = { by lemma 21 } 1.09/1.28 multiply(negative_part(X), Y) 1.09/1.28 1.09/1.28 Lemma 27: union(identity, X) = positive_part(X). 1.09/1.28 Proof: 1.09/1.28 union(identity, X) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(X, identity) 1.09/1.28 = { by axiom 13 (positive_part) } 1.09/1.28 positive_part(X) 1.09/1.28 1.09/1.28 Lemma 28: union(X, multiply(X, Y)) = multiply(X, positive_part(Y)). 1.09/1.28 Proof: 1.09/1.28 union(X, multiply(X, Y)) 1.09/1.28 = { by lemma 23 } 1.09/1.28 union(multiply(X, identity), multiply(X, Y)) 1.09/1.28 = { by axiom 9 (multiply_union1) } 1.09/1.28 multiply(X, union(identity, Y)) 1.09/1.28 = { by lemma 27 } 1.09/1.28 multiply(X, positive_part(Y)) 1.09/1.28 1.09/1.28 Lemma 29: union(X, union(Z, multiply(Y, X))) = union(Z, multiply(positive_part(Y), X)). 1.09/1.28 Proof: 1.09/1.28 union(X, union(Z, multiply(Y, X))) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(X, union(multiply(Y, X), Z)) 1.09/1.28 = { by axiom 14 (union_associative) } 1.09/1.28 union(union(X, multiply(Y, X)), Z) 1.09/1.28 = { by lemma 20 } 1.09/1.28 union(multiply(positive_part(Y), X), Z) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(Z, multiply(positive_part(Y), X)) 1.09/1.28 1.09/1.28 Lemma 30: union(X, union(Y, Z)) = union(Z, union(X, Y)). 1.09/1.28 Proof: 1.09/1.28 union(X, union(Y, Z)) 1.09/1.28 = { by axiom 14 (union_associative) } 1.09/1.28 union(union(X, Y), Z) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(Z, union(X, Y)) 1.09/1.28 1.09/1.28 Lemma 31: union(X, intersection(Y, X)) = X. 1.09/1.28 Proof: 1.09/1.28 union(X, intersection(Y, X)) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(intersection(Y, X), X) 1.09/1.28 = { by axiom 17 (union_intersection_absorbtion) } 1.09/1.28 X 1.09/1.28 1.09/1.28 Lemma 32: positive_part(negative_part(X)) = identity. 1.09/1.28 Proof: 1.09/1.28 positive_part(negative_part(X)) 1.09/1.28 = { by axiom 15 (negative_part) } 1.09/1.28 positive_part(intersection(X, identity)) 1.09/1.28 = { by lemma 27 } 1.09/1.28 union(identity, intersection(X, identity)) 1.09/1.28 = { by lemma 31 } 1.09/1.28 identity 1.09/1.28 1.09/1.28 Lemma 33: positive_part(union(X, Y)) = union(X, positive_part(Y)). 1.09/1.28 Proof: 1.09/1.28 positive_part(union(X, Y)) 1.09/1.28 = { by axiom 13 (positive_part) } 1.09/1.28 union(union(X, Y), identity) 1.09/1.28 = { by axiom 14 (union_associative) } 1.09/1.28 union(X, union(Y, identity)) 1.09/1.28 = { by axiom 13 (positive_part) } 1.09/1.28 union(X, positive_part(Y)) 1.09/1.28 1.09/1.28 Lemma 34: union(X, positive_part(multiply(Y, X))) = positive_part(multiply(positive_part(Y), X)). 1.09/1.28 Proof: 1.09/1.28 union(X, positive_part(multiply(Y, X))) 1.09/1.28 = { by lemma 33 } 1.09/1.28 positive_part(union(X, multiply(Y, X))) 1.09/1.28 = { by lemma 20 } 1.09/1.28 positive_part(multiply(positive_part(Y), X)) 1.09/1.28 1.09/1.28 Lemma 35: union(negative_part(X), positive_part(Y)) = positive_part(Y). 1.09/1.28 Proof: 1.09/1.28 union(negative_part(X), positive_part(Y)) 1.09/1.28 = { by axiom 5 (union_commutative) } 1.09/1.28 union(positive_part(Y), negative_part(X)) 1.09/1.28 = { by lemma 27 } 1.09/1.28 union(union(identity, Y), negative_part(X)) 1.09/1.28 = { by axiom 14 (union_associative) } 1.09/1.28 union(identity, union(Y, negative_part(X))) 1.09/1.28 = { by lemma 27 } 1.09/1.28 positive_part(union(Y, negative_part(X))) 1.09/1.28 = { by lemma 33 } 1.09/1.28 union(Y, positive_part(negative_part(X))) 1.09/1.28 = { by lemma 32 } 1.09/1.28 union(Y, identity) 1.09/1.28 = { by axiom 13 (positive_part) } 1.09/1.28 positive_part(Y) 1.09/1.28 1.09/1.28 Lemma 36: negative_part(positive_part(X)) = identity. 1.09/1.28 Proof: 1.09/1.28 negative_part(positive_part(X)) 1.09/1.28 = { by axiom 13 (positive_part) } 1.09/1.28 negative_part(union(X, identity)) 1.09/1.28 = { by lemma 21 } 1.09/1.28 intersection(identity, union(X, identity)) 1.09/1.28 = { by axiom 4 (intersection_commutative) } 1.09/1.28 intersection(union(X, identity), identity) 1.09/1.28 = { by axiom 6 (intersection_union_absorbtion) } 1.36/1.53 identity 1.36/1.53 1.36/1.53 Goal 1 (prove_product): a = multiply(positive_part(a), negative_part(a)). 1.36/1.53 Proof: 1.36/1.53 a 1.36/1.53 = { by lemma 19 } 1.36/1.53 multiply(inverse(negative_part(inverse(a))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 19 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), multiply(positive_part(a), negative_part(inverse(a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 25 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), multiply(positive_part(inverse(a)), negative_part(a)))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 3 (left_identity) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), multiply(identity, multiply(positive_part(inverse(a)), negative_part(a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 32 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), multiply(positive_part(negative_part(multiply(positive_part(inverse(a)), negative_part(a)))), multiply(positive_part(inverse(a)), negative_part(a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 20 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(inverse(a)), negative_part(a)), multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 5 (union_commutative) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 31 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))), union(multiply(positive_part(inverse(a)), negative_part(a)), intersection(identity, multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 21 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))), union(multiply(positive_part(inverse(a)), negative_part(a)), negative_part(multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 30 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), union(multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 30 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(inverse(a)), negative_part(a)), union(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 25 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), union(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 28 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(negative_part(multiply(positive_part(inverse(a)), negative_part(a))), positive_part(multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 26 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), intersection(positive_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(multiply(positive_part(inverse(a)), negative_part(a)), positive_part(multiply(positive_part(inverse(a)), negative_part(a)))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 23 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), intersection(multiply(positive_part(multiply(positive_part(inverse(a)), negative_part(a))), identity), multiply(multiply(positive_part(inverse(a)), negative_part(a)), positive_part(multiply(positive_part(inverse(a)), negative_part(a)))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 28 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), intersection(multiply(positive_part(multiply(positive_part(inverse(a)), negative_part(a))), identity), union(multiply(positive_part(inverse(a)), negative_part(a)), multiply(multiply(positive_part(inverse(a)), negative_part(a)), multiply(positive_part(inverse(a)), negative_part(a)))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 20 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), intersection(multiply(positive_part(multiply(positive_part(inverse(a)), negative_part(a))), identity), multiply(positive_part(multiply(positive_part(inverse(a)), negative_part(a))), multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 11 (multiply_intersection1) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(positive_part(multiply(positive_part(inverse(a)), negative_part(a))), intersection(identity, multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 34 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(union(negative_part(a), positive_part(multiply(inverse(a), negative_part(a)))), intersection(identity, multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 24 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(union(negative_part(a), positive_part(negative_part(inverse(a)))), intersection(identity, multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 35 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(positive_part(negative_part(inverse(a))), intersection(identity, multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 32 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(identity, intersection(identity, multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 21 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(identity, negative_part(multiply(positive_part(inverse(a)), negative_part(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 3 (left_identity) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), negative_part(multiply(positive_part(inverse(a)), negative_part(a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 7 (inverse_involution) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), negative_part(multiply(inverse(inverse(positive_part(inverse(a)))), negative_part(a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 22 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(inverse(positive_part(inverse(a))), negative_part(a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 15 (negative_part) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(inverse(positive_part(inverse(a))), intersection(a, identity)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 10 (intersection_associative) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(intersection(inverse(positive_part(inverse(a))), a), identity))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 15 (negative_part) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), negative_part(intersection(inverse(positive_part(inverse(a))), a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 21 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(identity, intersection(inverse(positive_part(inverse(a))), a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 10 (intersection_associative) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(intersection(identity, inverse(positive_part(inverse(a)))), a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 21 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(negative_part(inverse(positive_part(inverse(a)))), a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 4 (intersection_commutative) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(a, negative_part(inverse(positive_part(inverse(a))))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 15 (negative_part) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(a, intersection(inverse(positive_part(inverse(a))), identity)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 1 (left_inverse) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(a, intersection(inverse(positive_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), inverse(positive_part(inverse(a)))))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 7 (inverse_involution) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(a, intersection(inverse(positive_part(inverse(a))), multiply(positive_part(inverse(a)), inverse(positive_part(inverse(a)))))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 26 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(a, multiply(negative_part(positive_part(inverse(a))), inverse(positive_part(inverse(a))))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 36 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(a, multiply(identity, inverse(positive_part(inverse(a))))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 3 (left_identity) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(a, inverse(positive_part(inverse(a)))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 4 (intersection_commutative) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), multiply(inverse(inverse(positive_part(inverse(a)))), intersection(inverse(positive_part(inverse(a))), a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 22 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), negative_part(multiply(inverse(inverse(positive_part(inverse(a)))), a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 7 (inverse_involution) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), negative_part(multiply(positive_part(inverse(a)), a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 20 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), negative_part(union(a, multiply(inverse(a), a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 1 (left_inverse) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), negative_part(union(a, identity))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 13 (positive_part) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), negative_part(positive_part(a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 36 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(multiply(positive_part(a), negative_part(inverse(a))), identity))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 13 (positive_part) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), positive_part(multiply(positive_part(a), negative_part(inverse(a)))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 34 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(negative_part(inverse(a)), positive_part(multiply(a, negative_part(inverse(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 7 (inverse_involution) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(negative_part(inverse(a)), positive_part(multiply(inverse(inverse(a)), negative_part(inverse(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 24 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(negative_part(inverse(a)), positive_part(negative_part(inverse(inverse(a))))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 7 (inverse_involution) } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), union(negative_part(inverse(a)), positive_part(negative_part(a))))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 35 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), positive_part(negative_part(a)))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 32 } 1.36/1.53 multiply(inverse(multiply(inverse(positive_part(a)), identity)), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 23 } 1.36/1.53 multiply(inverse(inverse(positive_part(a))), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by axiom 7 (inverse_involution) } 1.36/1.53 multiply(positive_part(a), multiply(negative_part(inverse(a)), a)) 1.36/1.53 = { by lemma 26 } 1.36/1.53 multiply(positive_part(a), intersection(a, multiply(inverse(a), a))) 1.36/1.53 = { by axiom 1 (left_inverse) } 1.36/1.53 multiply(positive_part(a), intersection(a, identity)) 1.36/1.53 = { by axiom 15 (negative_part) } 1.36/1.53 multiply(positive_part(a), negative_part(a)) 1.36/1.53 % SZS output end Proof 1.36/1.53 1.36/1.53 RESULT: Unsatisfiable (the axioms are contradictory). 1.36/1.53 EOF