0.07/0.12 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.07/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.12/0.33 % Computer : n010.cluster.edu 0.12/0.33 % Model : x86_64 x86_64 0.12/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.12/0.33 % Memory : 8042.1875MB 0.12/0.33 % OS : Linux 3.10.0-693.el7.x86_64 0.12/0.33 % CPULimit : 180 0.12/0.33 % DateTime : Thu Aug 29 13:51:06 EDT 2019 0.12/0.33 % CPUTime : 21.30/21.52 % SZS status Unsatisfiable 21.30/21.52 21.30/21.52 % SZS output start Proof 21.30/21.52 Take the following subset of the input axioms: 21.37/21.54 fof(composition_associativity_5, axiom, ![A, B, C]: composition(composition(A, B), C)=composition(A, composition(B, C))). 21.37/21.54 fof(composition_distributivity_7, axiom, ![A, B, C]: composition(join(A, B), C)=join(composition(A, C), composition(B, C))). 21.37/21.54 fof(composition_identity_6, axiom, ![A]: A=composition(A, one)). 21.37/21.54 fof(converse_additivity_9, axiom, ![A, B]: join(converse(A), converse(B))=converse(join(A, B))). 21.37/21.54 fof(converse_cancellativity_11, axiom, ![A, B]: join(composition(converse(A), complement(composition(A, B))), complement(B))=complement(B)). 21.37/21.54 fof(converse_idempotence_8, axiom, ![A]: converse(converse(A))=A). 21.37/21.54 fof(converse_multiplicativity_10, axiom, ![A, B]: converse(composition(A, B))=composition(converse(B), converse(A))). 21.37/21.54 fof(def_top_12, axiom, ![A]: join(A, complement(A))=top). 21.37/21.54 fof(def_zero_13, axiom, ![A]: zero=meet(A, complement(A))). 21.37/21.54 fof(goals_14, negated_conjecture, complement(sk3)=join(composition(complement(sk1), sk2), complement(sk3))). 21.37/21.54 fof(goals_15, negated_conjecture, sk1!=join(composition(sk3, converse(sk2)), sk1)). 21.37/21.54 fof(maddux1_join_commutativity_1, axiom, ![A, B]: join(B, A)=join(A, B)). 21.37/21.54 fof(maddux2_join_associativity_2, axiom, ![A, B, C]: join(join(A, B), C)=join(A, join(B, C))). 21.37/21.54 fof(maddux3_a_kind_of_de_Morgan_3, axiom, ![A, B]: join(complement(join(complement(A), complement(B))), complement(join(complement(A), B)))=A). 21.37/21.54 fof(maddux4_definiton_of_meet_4, axiom, ![A, B]: complement(join(complement(A), complement(B)))=meet(A, B)). 21.37/21.54 21.37/21.54 Now clausify the problem and encode Horn clauses using encoding 3 of 21.37/21.54 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 21.37/21.54 We repeatedly replace C & s=t => u=v by the two clauses: 21.37/21.54 fresh(y, y, x1...xn) = u 21.37/21.54 C => fresh(s, t, x1...xn) = v 21.37/21.54 where fresh is a fresh function symbol and x1..xn are the free 21.37/21.54 variables of u and v. 21.37/21.54 A predicate p(X) is encoded as p(X)=true (this is sound, because the 21.37/21.54 input problem has no model of domain size 1). 21.37/21.54 21.37/21.54 The encoding turns the above axioms into the following unit equations and goals: 21.37/21.54 21.37/21.54 Axiom 1 (maddux1_join_commutativity_1): join(X, Y) = join(Y, X). 21.37/21.54 Axiom 2 (maddux4_definiton_of_meet_4): complement(join(complement(X), complement(Y))) = meet(X, Y). 21.37/21.54 Axiom 3 (composition_identity_6): X = composition(X, one). 21.37/21.54 Axiom 4 (maddux3_a_kind_of_de_Morgan_3): join(complement(join(complement(X), complement(Y))), complement(join(complement(X), Y))) = X. 21.37/21.54 Axiom 5 (converse_idempotence_8): converse(converse(X)) = X. 21.37/21.55 Axiom 6 (maddux2_join_associativity_2): join(join(X, Y), Z) = join(X, join(Y, Z)). 21.37/21.55 Axiom 7 (converse_cancellativity_11): join(composition(converse(X), complement(composition(X, Y))), complement(Y)) = complement(Y). 21.37/21.55 Axiom 8 (def_zero_13): zero = meet(X, complement(X)). 21.37/21.55 Axiom 9 (def_top_12): join(X, complement(X)) = top. 21.37/21.55 Axiom 10 (converse_multiplicativity_10): converse(composition(X, Y)) = composition(converse(Y), converse(X)). 21.37/21.55 Axiom 11 (converse_additivity_9): join(converse(X), converse(Y)) = converse(join(X, Y)). 21.37/21.55 Axiom 12 (composition_associativity_5): composition(composition(X, Y), Z) = composition(X, composition(Y, Z)). 21.37/21.55 Axiom 13 (composition_distributivity_7): composition(join(X, Y), Z) = join(composition(X, Z), composition(Y, Z)). 21.37/21.55 Axiom 14 (goals_14): complement(sk3) = join(composition(complement(sk1), sk2), complement(sk3)). 21.37/21.55 21.37/21.55 Lemma 15: meet(X, Y) = meet(Y, X). 21.37/21.55 Proof: 21.37/21.55 meet(X, Y) 21.37/21.55 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.55 complement(join(complement(X), complement(Y))) 21.37/21.55 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.55 complement(join(complement(Y), complement(X))) 21.37/21.55 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.55 meet(Y, X) 21.37/21.55 21.37/21.55 Lemma 16: complement(top) = zero. 21.37/21.55 Proof: 21.37/21.55 complement(top) 21.37/21.55 = { by axiom 9 (def_top_12) } 21.37/21.55 complement(join(complement(?), complement(complement(?)))) 21.37/21.55 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.55 meet(?, complement(?)) 21.37/21.55 = { by axiom 8 (def_zero_13) } 21.37/21.55 zero 21.37/21.55 21.37/21.55 Lemma 17: complement(join(zero, complement(X))) = meet(X, top). 21.37/21.55 Proof: 21.37/21.55 complement(join(zero, complement(X))) 21.37/21.55 = { by lemma 16 } 21.37/21.55 complement(join(complement(top), complement(X))) 21.37/21.55 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.55 meet(top, X) 21.37/21.55 = { by lemma 15 } 21.37/21.55 meet(X, top) 21.37/21.55 21.37/21.55 Lemma 18: converse(composition(converse(X), Y)) = composition(converse(Y), X). 21.37/21.55 Proof: 21.37/21.55 converse(composition(converse(X), Y)) 21.37/21.55 = { by axiom 10 (converse_multiplicativity_10) } 21.37/21.55 composition(converse(Y), converse(converse(X))) 21.37/21.55 = { by axiom 5 (converse_idempotence_8) } 21.37/21.55 composition(converse(Y), X) 21.37/21.55 21.37/21.55 Lemma 19: composition(converse(one), X) = X. 21.37/21.55 Proof: 21.37/21.55 composition(converse(one), X) 21.37/21.55 = { by lemma 18 } 21.37/21.55 converse(composition(converse(X), one)) 21.37/21.55 = { by axiom 3 (composition_identity_6) } 21.37/21.55 converse(converse(X)) 21.37/21.55 = { by axiom 5 (converse_idempotence_8) } 21.37/21.55 X 21.37/21.55 21.37/21.55 Lemma 20: join(complement(Y), composition(converse(X), complement(composition(X, Y)))) = complement(Y). 21.37/21.55 Proof: 21.37/21.55 join(complement(Y), composition(converse(X), complement(composition(X, Y)))) 21.37/21.55 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.55 join(composition(converse(X), complement(composition(X, Y))), complement(Y)) 21.37/21.55 = { by axiom 7 (converse_cancellativity_11) } 21.37/21.55 complement(Y) 21.37/21.55 21.37/21.55 Lemma 21: join(complement(X), complement(X)) = complement(X). 21.37/21.55 Proof: 21.37/21.55 join(complement(X), complement(X)) 21.37/21.55 = { by lemma 19 } 21.37/21.55 join(complement(X), composition(converse(one), complement(X))) 21.37/21.55 = { by lemma 19 } 21.37/21.55 join(complement(X), composition(converse(one), complement(composition(converse(one), X)))) 21.37/21.55 = { by axiom 3 (composition_identity_6) } 21.37/21.55 join(complement(X), composition(converse(one), complement(composition(composition(converse(one), one), X)))) 21.37/21.55 = { by axiom 12 (composition_associativity_5) } 21.37/21.55 join(complement(X), composition(converse(one), complement(composition(converse(one), composition(one, X))))) 21.37/21.55 = { by lemma 19 } 21.37/21.55 join(complement(X), composition(converse(one), complement(composition(one, X)))) 21.37/21.55 = { by lemma 20 } 21.37/21.55 complement(X) 21.37/21.55 21.37/21.55 Lemma 22: meet(X, X) = complement(complement(X)). 21.37/21.55 Proof: 21.37/21.55 meet(X, X) 21.37/21.55 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.55 complement(join(complement(X), complement(X))) 21.37/21.55 = { by lemma 21 } 21.37/21.55 complement(complement(X)) 21.37/21.55 21.37/21.55 Lemma 23: join(meet(X, Y), complement(join(complement(X), Y))) = X. 21.37/21.55 Proof: 21.37/21.55 join(meet(X, Y), complement(join(complement(X), Y))) 21.37/21.55 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.55 join(complement(join(complement(X), complement(Y))), complement(join(complement(X), Y))) 21.37/21.55 = { by axiom 4 (maddux3_a_kind_of_de_Morgan_3) } 21.37/21.55 X 21.37/21.55 21.37/21.55 Lemma 24: join(meet(X, Y), meet(X, complement(Y))) = X. 21.37/21.55 Proof: 21.37/21.55 join(meet(X, Y), meet(X, complement(Y))) 21.37/21.55 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.55 join(meet(X, complement(Y)), meet(X, Y)) 21.37/21.55 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.55 join(meet(X, complement(Y)), complement(join(complement(X), complement(Y)))) 21.37/21.55 = { by lemma 23 } 21.37/21.55 X 21.37/21.55 21.37/21.55 Lemma 25: join(zero, complement(complement(X))) = X. 21.37/21.55 Proof: 21.37/21.55 join(zero, complement(complement(X))) 21.37/21.55 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.55 join(complement(complement(X)), zero) 21.37/21.55 = { by lemma 22 } 21.37/21.55 join(meet(X, X), zero) 21.37/21.55 = { by axiom 8 (def_zero_13) } 21.37/21.55 join(meet(X, X), meet(X, complement(X))) 21.37/21.55 = { by lemma 24 } 21.37/21.55 X 21.37/21.55 21.37/21.55 Lemma 26: join(X, join(Y, Z)) = join(Z, join(X, Y)). 21.37/21.55 Proof: 21.37/21.55 join(X, join(Y, Z)) 21.37/21.55 = { by axiom 6 (maddux2_join_associativity_2) } 21.37/21.55 join(join(X, Y), Z) 21.37/21.55 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.55 join(Z, join(X, Y)) 21.37/21.55 21.37/21.55 Lemma 27: join(X, join(complement(X), Y)) = join(Y, top). 21.37/21.55 Proof: 21.37/21.55 join(X, join(complement(X), Y)) 21.37/21.55 = { by lemma 26 } 21.37/21.55 join(complement(X), join(Y, X)) 21.37/21.55 = { by lemma 26 } 21.37/21.55 join(Y, join(X, complement(X))) 21.37/21.55 = { by axiom 9 (def_top_12) } 21.37/21.55 join(Y, top) 21.37/21.55 21.37/21.55 Lemma 28: join(X, top) = top. 21.37/21.55 Proof: 21.37/21.55 join(X, top) 21.37/21.55 = { by axiom 9 (def_top_12) } 21.37/21.55 join(X, join(complement(X), complement(complement(X)))) 21.37/21.55 = { by lemma 27 } 21.37/21.55 join(complement(complement(X)), top) 21.37/21.55 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.55 join(top, complement(complement(X))) 21.37/21.55 = { by axiom 9 (def_top_12) } 21.37/21.55 join(join(complement(X), complement(complement(X))), complement(complement(X))) 21.37/21.55 = { by axiom 6 (maddux2_join_associativity_2) } 21.37/21.55 join(complement(X), join(complement(complement(X)), complement(complement(X)))) 21.37/21.55 = { by lemma 21 } 21.37/21.55 join(complement(X), complement(complement(X))) 21.37/21.55 = { by axiom 9 (def_top_12) } 21.37/21.55 top 21.37/21.55 21.37/21.55 Lemma 29: join(zero, meet(X, top)) = X. 21.37/21.55 Proof: 21.37/21.55 join(zero, meet(X, top)) 21.37/21.55 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.55 join(meet(X, top), zero) 21.37/21.55 = { by lemma 16 } 21.37/21.55 join(meet(X, top), complement(top)) 21.37/21.55 = { by lemma 28 } 21.37/21.55 join(meet(X, top), complement(join(complement(X), top))) 21.37/21.55 = { by lemma 23 } 21.37/21.55 X 21.37/21.55 21.37/21.55 Lemma 30: join(zero, complement(X)) = complement(X). 21.37/21.55 Proof: 21.37/21.55 join(zero, complement(X)) 21.37/21.55 = { by lemma 25 } 21.37/21.55 join(zero, complement(join(zero, complement(complement(X))))) 21.37/21.55 = { by lemma 17 } 21.37/21.55 join(zero, meet(complement(X), top)) 21.37/21.55 = { by lemma 29 } 21.37/21.55 complement(X) 21.37/21.55 21.37/21.55 Lemma 31: complement(complement(X)) = X. 21.37/21.55 Proof: 21.37/21.55 complement(complement(X)) 21.37/21.55 = { by lemma 30 } 21.37/21.55 join(zero, complement(complement(X))) 21.37/21.55 = { by lemma 25 } 21.37/21.55 X 21.37/21.55 21.37/21.55 Lemma 32: meet(X, top) = X. 21.37/21.55 Proof: 21.37/21.55 meet(X, top) 21.37/21.55 = { by lemma 17 } 21.37/21.55 complement(join(zero, complement(X))) 21.37/21.55 = { by lemma 30 } 21.37/21.55 join(zero, complement(join(zero, complement(X)))) 21.37/21.55 = { by lemma 17 } 21.37/21.55 join(zero, meet(X, top)) 21.37/21.55 = { by lemma 29 } 21.37/21.55 X 21.37/21.55 21.37/21.55 Lemma 33: meet(top, X) = X. 21.37/21.55 Proof: 21.37/21.55 meet(top, X) 21.37/21.55 = { by lemma 15 } 21.37/21.55 meet(X, top) 21.37/21.55 = { by lemma 32 } 21.37/21.56 X 21.37/21.56 21.37/21.56 Lemma 34: complement(join(X, complement(Y))) = meet(Y, complement(X)). 21.37/21.56 Proof: 21.37/21.56 complement(join(X, complement(Y))) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 complement(join(complement(Y), X)) 21.37/21.56 = { by lemma 33 } 21.37/21.56 complement(join(complement(Y), meet(top, X))) 21.37/21.56 = { by lemma 15 } 21.37/21.56 complement(join(complement(Y), meet(X, top))) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 complement(join(meet(X, top), complement(Y))) 21.37/21.56 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.56 complement(join(complement(join(complement(X), complement(top))), complement(Y))) 21.37/21.56 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.56 meet(join(complement(X), complement(top)), Y) 21.37/21.56 = { by lemma 15 } 21.37/21.56 meet(Y, join(complement(X), complement(top))) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 meet(Y, join(complement(top), complement(X))) 21.37/21.56 = { by lemma 16 } 21.37/21.56 meet(Y, join(zero, complement(X))) 21.37/21.56 = { by lemma 30 } 21.37/21.56 meet(Y, complement(X)) 21.37/21.56 21.37/21.56 Lemma 35: meet(complement(X), complement(Y)) = complement(join(X, Y)). 21.37/21.56 Proof: 21.37/21.56 meet(complement(X), complement(Y)) 21.37/21.56 = { by lemma 30 } 21.37/21.56 meet(join(zero, complement(X)), complement(Y)) 21.37/21.56 = { by lemma 34 } 21.37/21.56 complement(join(Y, complement(join(zero, complement(X))))) 21.37/21.56 = { by lemma 17 } 21.37/21.56 complement(join(Y, meet(X, top))) 21.37/21.56 = { by lemma 32 } 21.37/21.56 complement(join(Y, X)) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 complement(join(X, Y)) 21.37/21.56 21.37/21.56 Lemma 36: complement(join(complement(X), Y)) = meet(X, complement(Y)). 21.37/21.56 Proof: 21.37/21.56 complement(join(complement(X), Y)) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 complement(join(Y, complement(X))) 21.37/21.56 = { by lemma 34 } 21.37/21.56 meet(X, complement(Y)) 21.37/21.56 21.37/21.56 Lemma 37: join(meet(Y, X), meet(X, complement(Y))) = X. 21.37/21.56 Proof: 21.37/21.56 join(meet(Y, X), meet(X, complement(Y))) 21.37/21.56 = { by lemma 15 } 21.37/21.56 join(meet(X, Y), meet(X, complement(Y))) 21.37/21.56 = { by lemma 24 } 21.37/21.56 X 21.37/21.56 21.37/21.56 Lemma 38: join(X, zero) = X. 21.37/21.56 Proof: 21.37/21.56 join(X, zero) 21.37/21.56 = { by lemma 31 } 21.37/21.56 join(complement(complement(X)), zero) 21.37/21.56 = { by lemma 22 } 21.37/21.56 join(meet(X, X), zero) 21.37/21.56 = { by axiom 8 (def_zero_13) } 21.37/21.56 join(meet(X, X), meet(X, complement(X))) 21.37/21.56 = { by lemma 37 } 21.37/21.56 X 21.37/21.56 21.37/21.56 Lemma 39: meet(meet(X, Z), Y) = meet(X, meet(Y, Z)). 21.37/21.56 Proof: 21.37/21.56 meet(meet(X, Z), Y) 21.37/21.56 = { by lemma 15 } 21.37/21.56 meet(Y, meet(X, Z)) 21.37/21.56 = { by lemma 32 } 21.37/21.56 meet(meet(Y, top), meet(X, Z)) 21.37/21.56 = { by lemma 17 } 21.37/21.56 meet(complement(join(zero, complement(Y))), meet(X, Z)) 21.37/21.56 = { by lemma 15 } 21.37/21.56 meet(meet(X, Z), complement(join(zero, complement(Y)))) 21.37/21.56 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.56 meet(complement(join(complement(X), complement(Z))), complement(join(zero, complement(Y)))) 21.37/21.56 = { by lemma 35 } 21.37/21.56 complement(join(join(complement(X), complement(Z)), join(zero, complement(Y)))) 21.37/21.56 = { by axiom 6 (maddux2_join_associativity_2) } 21.37/21.56 complement(join(complement(X), join(complement(Z), join(zero, complement(Y))))) 21.37/21.56 = { by lemma 36 } 21.37/21.56 meet(X, complement(join(complement(Z), join(zero, complement(Y))))) 21.37/21.56 = { by lemma 36 } 21.37/21.56 meet(X, meet(Z, complement(join(zero, complement(Y))))) 21.37/21.56 = { by lemma 17 } 21.37/21.56 meet(X, meet(Z, meet(Y, top))) 21.37/21.56 = { by lemma 32 } 21.37/21.56 meet(X, meet(Z, Y)) 21.37/21.56 = { by lemma 15 } 21.37/21.56 meet(X, meet(Y, Z)) 21.37/21.56 21.37/21.56 Lemma 40: meet(X, join(X, Y)) = X. 21.37/21.56 Proof: 21.37/21.56 meet(X, join(X, Y)) 21.37/21.56 = { by axiom 5 (converse_idempotence_8) } 21.37/21.56 meet(converse(converse(X)), join(X, Y)) 21.37/21.56 = { by axiom 5 (converse_idempotence_8) } 21.37/21.56 meet(converse(converse(X)), converse(converse(join(X, Y)))) 21.37/21.56 = { by axiom 11 (converse_additivity_9) } 21.37/21.56 meet(converse(converse(X)), converse(join(converse(X), converse(Y)))) 21.37/21.56 = { by lemma 38 } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), zero) 21.37/21.56 = { by lemma 16 } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), complement(top)) 21.37/21.56 = { by lemma 28 } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), complement(join(converse(converse(Y)), top))) 21.37/21.56 = { by axiom 9 (def_top_12) } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), complement(join(converse(converse(Y)), join(converse(converse(X)), complement(converse(converse(X))))))) 21.37/21.56 = { by axiom 6 (maddux2_join_associativity_2) } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), complement(join(join(converse(converse(Y)), converse(converse(X))), complement(converse(converse(X)))))) 21.37/21.56 = { by axiom 11 (converse_additivity_9) } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), complement(join(converse(join(converse(Y), converse(X))), complement(converse(converse(X)))))) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), complement(join(complement(converse(converse(X))), converse(join(converse(Y), converse(X)))))) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 join(meet(converse(converse(X)), converse(join(converse(X), converse(Y)))), complement(join(complement(converse(converse(X))), converse(join(converse(X), converse(Y)))))) 21.37/21.56 = { by lemma 23 } 21.37/21.56 converse(converse(X)) 21.37/21.56 = { by axiom 5 (converse_idempotence_8) } 21.37/21.56 X 21.37/21.56 21.37/21.56 Lemma 41: meet(complement(X), join(X, Y)) = meet(Y, complement(X)). 21.37/21.56 Proof: 21.37/21.56 meet(complement(X), join(X, Y)) 21.37/21.56 = { by lemma 31 } 21.37/21.56 meet(complement(X), join(X, complement(complement(Y)))) 21.37/21.56 = { by lemma 24 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(meet(complement(X), join(X, complement(complement(Y)))), complement(Y))) 21.37/21.56 = { by lemma 15 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(complement(Y), meet(complement(X), join(X, complement(complement(Y)))))) 21.37/21.56 = { by lemma 15 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(complement(Y), meet(join(X, complement(complement(Y))), complement(X)))) 21.37/21.56 = { by lemma 36 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(complement(Y), complement(join(complement(join(X, complement(complement(Y)))), X)))) 21.37/21.56 = { by lemma 36 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), complement(join(complement(complement(Y)), join(complement(join(X, complement(complement(Y)))), X)))) 21.37/21.56 = { by axiom 6 (maddux2_join_associativity_2) } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), complement(join(join(complement(complement(Y)), complement(join(X, complement(complement(Y))))), X))) 21.37/21.56 = { by lemma 35 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(complement(join(complement(complement(Y)), complement(join(X, complement(complement(Y)))))), complement(X))) 21.37/21.56 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(meet(complement(Y), join(X, complement(complement(Y)))), complement(X))) 21.37/21.56 = { by lemma 15 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(complement(X), meet(complement(Y), join(X, complement(complement(Y)))))) 21.37/21.56 = { by lemma 15 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(complement(X), meet(join(X, complement(complement(Y))), complement(Y)))) 21.37/21.56 = { by lemma 15 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(meet(join(X, complement(complement(Y))), complement(Y)), complement(X))) 21.37/21.56 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(complement(join(complement(join(X, complement(complement(Y)))), complement(complement(Y)))), complement(X))) 21.37/21.56 = { by lemma 35 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), complement(join(join(complement(join(X, complement(complement(Y)))), complement(complement(Y))), X))) 21.37/21.56 = { by axiom 6 (maddux2_join_associativity_2) } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), complement(join(complement(join(X, complement(complement(Y)))), join(complement(complement(Y)), X)))) 21.37/21.56 = { by lemma 36 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(join(X, complement(complement(Y))), complement(join(complement(complement(Y)), X)))) 21.37/21.56 = { by lemma 36 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(join(X, complement(complement(Y))), meet(complement(Y), complement(X)))) 21.37/21.56 = { by lemma 34 } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), meet(join(X, complement(complement(Y))), complement(join(X, complement(complement(Y)))))) 21.37/21.56 = { by axiom 8 (def_zero_13) } 21.37/21.56 join(meet(meet(complement(X), join(X, complement(complement(Y)))), Y), zero) 21.37/21.56 = { by lemma 38 } 21.37/21.56 meet(meet(complement(X), join(X, complement(complement(Y)))), Y) 21.37/21.56 = { by lemma 39 } 21.37/21.56 meet(complement(X), meet(Y, join(X, complement(complement(Y))))) 21.37/21.56 = { by lemma 31 } 21.37/21.56 meet(complement(X), meet(Y, join(X, Y))) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 meet(complement(X), meet(Y, join(Y, X))) 21.37/21.56 = { by lemma 40 } 21.37/21.56 meet(complement(X), Y) 21.37/21.56 = { by lemma 15 } 21.37/21.56 meet(Y, complement(X)) 21.37/21.56 21.37/21.56 Lemma 42: join(zero, X) = X. 21.37/21.56 Proof: 21.37/21.56 join(zero, X) 21.37/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.37/21.56 join(X, zero) 21.37/21.56 = { by lemma 38 } 21.39/21.56 X 21.39/21.56 21.39/21.56 Lemma 43: meet(join(X, Y), join(X, complement(Y))) = X. 21.39/21.56 Proof: 21.39/21.56 meet(join(X, Y), join(X, complement(Y))) 21.39/21.56 = { by lemma 32 } 21.39/21.56 meet(join(X, Y), meet(join(X, complement(Y)), top)) 21.39/21.56 = { by lemma 17 } 21.39/21.56 meet(join(X, Y), complement(join(zero, complement(join(X, complement(Y)))))) 21.39/21.56 = { by lemma 34 } 21.39/21.56 meet(join(X, Y), complement(join(zero, meet(Y, complement(X))))) 21.39/21.56 = { by lemma 42 } 21.39/21.56 meet(join(X, Y), complement(meet(Y, complement(X)))) 21.39/21.56 = { by lemma 36 } 21.39/21.56 complement(join(complement(join(X, Y)), meet(Y, complement(X)))) 21.39/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.56 complement(join(complement(join(Y, X)), meet(Y, complement(X)))) 21.39/21.56 = { by lemma 15 } 21.39/21.56 complement(join(complement(join(Y, X)), meet(complement(X), Y))) 21.39/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.56 complement(join(meet(complement(X), Y), complement(join(Y, X)))) 21.39/21.56 = { by lemma 30 } 21.39/21.56 complement(join(meet(join(zero, complement(X)), Y), complement(join(Y, X)))) 21.39/21.56 = { by lemma 32 } 21.39/21.56 complement(join(meet(join(zero, complement(X)), Y), complement(join(Y, meet(X, top))))) 21.39/21.56 = { by lemma 17 } 21.39/21.56 complement(join(meet(join(zero, complement(X)), Y), complement(join(Y, complement(join(zero, complement(X))))))) 21.39/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.56 complement(join(meet(join(zero, complement(X)), Y), complement(join(complement(join(zero, complement(X))), Y)))) 21.39/21.56 = { by lemma 23 } 21.39/21.56 complement(join(zero, complement(X))) 21.39/21.56 = { by lemma 30 } 21.39/21.56 complement(complement(X)) 21.39/21.56 = { by lemma 31 } 21.39/21.56 X 21.39/21.56 21.39/21.56 Lemma 44: converse(join(converse(X), Y)) = join(X, converse(Y)). 21.39/21.56 Proof: 21.39/21.56 converse(join(converse(X), Y)) 21.39/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.56 converse(join(Y, converse(X))) 21.39/21.56 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.56 converse(join(converse(X), Y)) 21.39/21.56 = { by axiom 11 (converse_additivity_9) } 21.39/21.56 join(converse(converse(X)), converse(Y)) 21.39/21.56 = { by axiom 5 (converse_idempotence_8) } 21.39/21.56 join(X, converse(Y)) 21.39/21.56 21.39/21.56 Lemma 45: join(X, converse(top)) = converse(top). 21.39/21.56 Proof: 21.39/21.56 join(X, converse(top)) 21.39/21.56 = { by lemma 44 } 21.39/21.56 converse(join(converse(X), top)) 21.39/21.56 = { by lemma 28 } 21.39/21.56 converse(top) 21.39/21.56 21.39/21.56 Lemma 46: join(X, converse(complement(converse(X)))) = top. 21.39/21.56 Proof: 21.39/21.56 join(X, converse(complement(converse(X)))) 21.39/21.56 = { by lemma 44 } 21.39/21.56 converse(join(converse(X), complement(converse(X)))) 21.39/21.56 = { by axiom 9 (def_top_12) } 21.39/21.56 converse(top) 21.39/21.56 = { by lemma 45 } 21.39/21.56 join(?, converse(top)) 21.39/21.56 = { by lemma 45 } 21.39/21.56 join(?, join(complement(?), converse(top))) 21.39/21.56 = { by lemma 27 } 21.39/21.56 join(converse(top), top) 21.39/21.56 = { by lemma 28 } 21.39/21.57 top 21.39/21.57 21.39/21.57 Lemma 47: converse(complement(converse(X))) = complement(X). 21.39/21.57 Proof: 21.39/21.57 converse(complement(converse(X))) 21.39/21.57 = { by lemma 32 } 21.39/21.57 converse(complement(converse(meet(X, top)))) 21.39/21.57 = { by lemma 17 } 21.39/21.57 converse(complement(converse(complement(join(zero, complement(X)))))) 21.39/21.57 = { by lemma 43 } 21.39/21.57 meet(join(converse(complement(converse(complement(join(zero, complement(X)))))), join(zero, complement(X))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.57 meet(join(join(zero, complement(X)), converse(complement(converse(complement(join(zero, complement(X))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by axiom 5 (converse_idempotence_8) } 21.39/21.57 meet(join(join(zero, complement(X)), converse(complement(converse(complement(converse(converse(join(zero, complement(X))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by lemma 44 } 21.39/21.57 meet(converse(join(converse(join(zero, complement(X))), complement(converse(complement(converse(converse(join(zero, complement(X))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by lemma 33 } 21.39/21.57 meet(converse(meet(top, join(converse(join(zero, complement(X))), complement(converse(complement(converse(converse(join(zero, complement(X)))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by lemma 46 } 21.39/21.57 meet(converse(meet(join(converse(join(zero, complement(X))), converse(complement(converse(converse(join(zero, complement(X))))))), join(converse(join(zero, complement(X))), complement(converse(complement(converse(converse(join(zero, complement(X)))))))))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by lemma 43 } 21.39/21.57 meet(converse(converse(join(zero, complement(X)))), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by axiom 5 (converse_idempotence_8) } 21.39/21.57 meet(join(zero, complement(X)), join(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(X))))) 21.39/21.57 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.57 meet(join(zero, complement(X)), join(complement(join(zero, complement(X))), converse(complement(converse(complement(join(zero, complement(X)))))))) 21.39/21.57 = { by lemma 42 } 21.39/21.57 meet(join(zero, complement(X)), join(zero, join(complement(join(zero, complement(X))), converse(complement(converse(complement(join(zero, complement(X))))))))) 21.39/21.57 = { by axiom 6 (maddux2_join_associativity_2) } 21.39/21.57 meet(join(zero, complement(X)), join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X)))))))) 21.39/21.57 = { by lemma 32 } 21.39/21.57 meet(join(zero, complement(X)), meet(join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X))))))), top)) 21.39/21.57 = { by lemma 39 } 21.39/21.57 meet(meet(join(zero, complement(X)), top), join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X)))))))) 21.39/21.57 = { by lemma 17 } 21.39/21.57 meet(complement(join(zero, complement(join(zero, complement(X))))), join(join(zero, complement(join(zero, complement(X)))), converse(complement(converse(complement(join(zero, complement(X)))))))) 21.39/21.57 = { by lemma 41 } 21.39/21.57 meet(converse(complement(converse(complement(join(zero, complement(X)))))), complement(join(zero, complement(join(zero, complement(X)))))) 21.39/21.57 = { by lemma 17 } 21.39/21.57 meet(converse(complement(converse(complement(join(zero, complement(X)))))), meet(join(zero, complement(X)), top)) 21.39/21.57 = { by lemma 32 } 21.39/21.57 meet(converse(complement(converse(complement(join(zero, complement(X)))))), join(zero, complement(X))) 21.39/21.57 = { by lemma 15 } 21.39/21.57 meet(join(zero, complement(X)), converse(complement(converse(complement(join(zero, complement(X))))))) 21.39/21.57 = { by axiom 2 (maddux4_definiton_of_meet_4) } 21.39/21.57 complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X))))))))) 21.39/21.57 = { by lemma 30 } 21.39/21.57 join(zero, complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 21.39/21.57 = { by lemma 16 } 21.39/21.57 join(complement(top), complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 21.39/21.57 = { by lemma 46 } 21.39/21.57 join(complement(join(complement(join(zero, complement(X))), converse(complement(converse(complement(join(zero, complement(X)))))))), complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 21.39/21.57 = { by lemma 36 } 21.39/21.57 join(meet(join(zero, complement(X)), complement(converse(complement(converse(complement(join(zero, complement(X)))))))), complement(join(complement(join(zero, complement(X))), complement(converse(complement(converse(complement(join(zero, complement(X)))))))))) 21.39/21.57 = { by lemma 23 } 21.39/21.57 join(zero, complement(X)) 21.39/21.57 = { by lemma 30 } 21.39/21.60 complement(X) 21.39/21.60 21.39/21.60 Goal 1 (goals_15): sk1 = join(composition(sk3, converse(sk2)), sk1). 21.39/21.60 Proof: 21.39/21.60 sk1 21.39/21.60 = { by lemma 38 } 21.39/21.60 join(sk1, zero) 21.39/21.60 = { by lemma 16 } 21.39/21.60 join(sk1, complement(top)) 21.39/21.60 = { by lemma 28 } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), top))) 21.39/21.60 = { by lemma 28 } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(composition(complement(join(complement(complement(composition(complement(sk1), sk2))), sk3)), converse(sk2)), top)))) 21.39/21.60 = { by axiom 9 (def_top_12) } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(composition(complement(join(complement(complement(composition(complement(sk1), sk2))), sk3)), converse(sk2)), join(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2)), complement(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2)))))))) 21.39/21.60 = { by axiom 6 (maddux2_join_associativity_2) } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(join(composition(complement(join(complement(complement(composition(complement(sk1), sk2))), sk3)), converse(sk2)), composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2))), complement(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2))))))) 21.39/21.60 = { by axiom 13 (composition_distributivity_7) } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(composition(join(complement(join(complement(complement(composition(complement(sk1), sk2))), sk3)), meet(complement(composition(complement(sk1), sk2)), sk3)), converse(sk2)), complement(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2))))))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(complement(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2))), composition(join(complement(join(complement(complement(composition(complement(sk1), sk2))), sk3)), meet(complement(composition(complement(sk1), sk2)), sk3)), converse(sk2)))))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(complement(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2))), composition(join(meet(complement(composition(complement(sk1), sk2)), sk3), complement(join(complement(complement(composition(complement(sk1), sk2))), sk3))), converse(sk2)))))) 21.39/21.60 = { by lemma 23 } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(complement(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2))), composition(complement(composition(complement(sk1), sk2)), converse(sk2)))))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(composition(complement(composition(complement(sk1), sk2)), converse(sk2)), complement(composition(meet(complement(composition(complement(sk1), sk2)), sk3), converse(sk2))))))) 21.39/21.60 = { by lemma 15 } 21.39/21.60 join(sk1, complement(join(complement(complement(sk1)), join(composition(complement(composition(complement(sk1), sk2)), converse(sk2)), complement(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2))))))) 21.39/21.60 = { by axiom 6 (maddux2_join_associativity_2) } 21.39/21.60 join(sk1, complement(join(join(complement(complement(sk1)), composition(complement(composition(complement(sk1), sk2)), converse(sk2))), complement(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)))))) 21.39/21.60 = { by lemma 34 } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(join(complement(complement(sk1)), composition(complement(composition(complement(sk1), sk2)), converse(sk2)))))) 21.39/21.60 = { by lemma 47 } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(join(converse(complement(converse(complement(sk1)))), composition(complement(composition(complement(sk1), sk2)), converse(sk2)))))) 21.39/21.60 = { by axiom 5 (converse_idempotence_8) } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(join(converse(complement(converse(complement(sk1)))), composition(complement(composition(complement(sk1), converse(converse(sk2)))), converse(sk2)))))) 21.39/21.60 = { by lemma 47 } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(join(converse(complement(converse(complement(sk1)))), composition(converse(complement(converse(composition(complement(sk1), converse(converse(sk2)))))), converse(sk2)))))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(join(composition(converse(complement(converse(composition(complement(sk1), converse(converse(sk2)))))), converse(sk2)), converse(complement(converse(complement(sk1)))))))) 21.39/21.60 = { by lemma 18 } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(join(converse(composition(converse(converse(sk2)), complement(converse(composition(complement(sk1), converse(converse(sk2))))))), converse(complement(converse(complement(sk1)))))))) 21.39/21.60 = { by axiom 11 (converse_additivity_9) } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(converse(join(composition(converse(converse(sk2)), complement(converse(composition(complement(sk1), converse(converse(sk2)))))), complement(converse(complement(sk1)))))))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(converse(join(complement(converse(complement(sk1))), composition(converse(converse(sk2)), complement(converse(composition(complement(sk1), converse(converse(sk2))))))))))) 21.39/21.60 = { by axiom 5 (converse_idempotence_8) } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(converse(join(complement(converse(complement(sk1))), composition(converse(converse(converse(converse(sk2)))), complement(converse(composition(complement(sk1), converse(converse(sk2))))))))))) 21.39/21.60 = { by axiom 10 (converse_multiplicativity_10) } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(converse(join(complement(converse(complement(sk1))), composition(converse(converse(converse(converse(sk2)))), complement(composition(converse(converse(converse(sk2))), converse(complement(sk1)))))))))) 21.39/21.60 = { by lemma 20 } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(converse(complement(converse(complement(sk1))))))) 21.39/21.60 = { by lemma 47 } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(complement(complement(sk1))))) 21.39/21.60 = { by lemma 31 } 21.39/21.60 join(sk1, meet(composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)), complement(sk1))) 21.39/21.60 = { by lemma 15 } 21.39/21.60 join(sk1, meet(complement(sk1), composition(meet(sk3, complement(composition(complement(sk1), sk2))), converse(sk2)))) 21.39/21.60 = { by lemma 36 } 21.39/21.60 join(sk1, meet(complement(sk1), composition(complement(join(complement(sk3), composition(complement(sk1), sk2))), converse(sk2)))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(sk1, meet(complement(sk1), composition(complement(join(composition(complement(sk1), sk2), complement(sk3))), converse(sk2)))) 21.39/21.60 = { by axiom 14 (goals_14) } 21.39/21.60 join(sk1, meet(complement(sk1), composition(complement(complement(sk3)), converse(sk2)))) 21.39/21.60 = { by lemma 31 } 21.39/21.60 join(sk1, meet(complement(sk1), composition(sk3, converse(sk2)))) 21.39/21.60 = { by lemma 15 } 21.39/21.60 join(sk1, meet(composition(sk3, converse(sk2)), complement(sk1))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(meet(composition(sk3, converse(sk2)), complement(sk1)), sk1) 21.39/21.60 = { by lemma 41 } 21.39/21.60 join(meet(complement(sk1), join(sk1, composition(sk3, converse(sk2)))), sk1) 21.39/21.60 = { by lemma 40 } 21.39/21.60 join(meet(complement(sk1), join(sk1, composition(sk3, converse(sk2)))), meet(sk1, join(sk1, composition(sk3, converse(sk2))))) 21.39/21.60 = { by lemma 31 } 21.39/21.60 join(meet(complement(sk1), join(sk1, composition(sk3, converse(sk2)))), meet(complement(complement(sk1)), join(sk1, composition(sk3, converse(sk2))))) 21.39/21.60 = { by lemma 15 } 21.39/21.60 join(meet(complement(sk1), join(sk1, composition(sk3, converse(sk2)))), meet(join(sk1, composition(sk3, converse(sk2))), complement(complement(sk1)))) 21.39/21.60 = { by lemma 37 } 21.39/21.60 join(sk1, composition(sk3, converse(sk2))) 21.39/21.60 = { by axiom 1 (maddux1_join_commutativity_1) } 21.39/21.60 join(composition(sk3, converse(sk2)), sk1) 21.39/21.60 % SZS output end Proof 21.39/21.60 21.39/21.60 RESULT: Unsatisfiable (the axioms are contradictory). 21.39/21.61 EOF