%------------------------------------------------------------------------------ % File : Otter---3.3 % Problem : SWX203+1 : TPTP v9.3.0. Released v9.3.0. % Transfm : none % Format : tptp:raw % Command : otter-tptp-script %s % Computer : n013.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 : Tue May 5 07:05:24 PM UTC 2026 % Result : Unknown 12.85s 13.04s % Output : None % Verified : % SZS Type : - % Comments : %------------------------------------------------------------------------------ %----No solution output by system %------------------------------------------------------------------------------ %----ORIGINAL SYSTEM OUTPUT % 0.00/0.12 % Problem : SWX203+1 : TPTP v9.3.0. Released v9.3.0. % 0.12/0.12 % Command : otter-tptp-script %s % 0.15/0.33 % Computer : n013.cluster.edu % 0.15/0.33 % Model : x86_64 x86_64 % 0.15/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz % 0.15/0.33 % Memory : 8042.1875MB % 0.15/0.33 % OS : Linux 3.10.0-693.el7.x86_64 % 0.15/0.33 % CPULimit : 300 % 0.15/0.33 % WCLimit : 300 % 0.15/0.33 % DateTime : Tue May 5 11:25:40 EDT 2026 % 0.15/0.33 % CPUTime : % 1.88/2.08 ----- Otter 3.3f, August 2004 ----- % 1.88/2.08 The process was started by sandbox on n013.cluster.edu, % 1.88/2.08 Tue May 5 11:25:40 2026 % 1.88/2.08 The command was "./otter". The process ID is 14728. % 1.88/2.08 % 1.88/2.08 set(prolog_style_variables). % 1.88/2.08 set(auto). % 1.88/2.08 dependent: set(auto1). % 1.88/2.08 dependent: set(process_input). % 1.88/2.08 dependent: clear(print_kept). % 1.88/2.08 dependent: clear(print_new_demod). % 1.88/2.08 dependent: clear(print_back_demod). % 1.88/2.08 dependent: clear(print_back_sub). % 1.88/2.08 dependent: set(control_memory). % 1.88/2.08 dependent: assign(max_mem, 12000). % 1.88/2.08 dependent: assign(pick_given_ratio, 4). % 1.88/2.08 dependent: assign(stats_level, 1). % 1.88/2.08 dependent: assign(max_seconds, 10800). % 1.88/2.08 clear(print_given). % 1.88/2.08 % 1.88/2.08 formula_list(usable). % 1.88/2.08 all A (A=A). % 1.88/2.08 all X X2 (head(cons(X,X2))=X). % 1.88/2.08 all X X2 (tail(cons(X,X2))=X2). % 1.88/2.08 all X X2 (nil!=cons(X,X2)). % 1.88/2.08 all X (proj1S(s(X))=X). % 1.88/2.08 all X (z!=s(X)). % 1.88/2.08 all Y le_qNat(z,Y). % 1.88/2.08 all Z (-le_qNat(s(Z),z)). % 1.88/2.08 all Z M (le_qNat(s(Z),s(M))<->le_qNat(Z,M)). % 1.88/2.08 sorted(nil). % 1.88/2.08 all Y sorted(cons(Y,nil)). % 1.88/2.08 all Y Y2 Xs (sorted(cons(Y,cons(Y2,Xs)))<->le_qNat(Y,Y2)&sorted(cons(Y2,Xs))). % 1.88/2.08 lengthNat(nil)=z. % 1.88/2.08 all Y Xs (lengthNat(cons(Y,Xs))=s(lengthNat(Xs))). % 1.88/2.08 all X (-elemNat(X,nil)). % 1.88/2.08 all X Z Xs (elemNat(X,cons(Z,Xs))<->X=Z|elemNat(X,Xs)). % 1.88/2.08 unique(nil). % 1.88/2.08 all Y Xs (unique(cons(Y,Xs))<-> -elemNat(Y,Xs)&unique(Xs)). % 1.88/2.08 all Y (append(nil,Y)=Y). % 1.88/2.08 all Y Z Xs (append(cons(Z,Xs),Y)=cons(Z,append(Xs,Y))). % 1.88/2.08 rev(nil)=nil. % 1.88/2.08 all Y Xs (rev(cons(Y,Xs))=append(rev(Xs),cons(Y,nil))). % 1.88/2.08 -(exists Xs (-(sorted(rev(Xs))-> (unique(Xs)->le_qNat(lengthNat(Xs),s(s(s(z)))))))). % 1.88/2.08 end_of_list. % 1.88/2.08 % 1.88/2.08 -------> usable clausifies to: % 1.88/2.08 % 1.88/2.08 list(usable). % 1.88/2.08 0 [] A=A. % 1.88/2.08 0 [] head(cons(X,X2))=X. % 1.88/2.08 0 [] tail(cons(X,X2))=X2. % 1.88/2.08 0 [] nil!=cons(X,X2). % 1.88/2.08 0 [] proj1S(s(X))=X. % 1.88/2.08 0 [] z!=s(X). % 1.88/2.08 0 [] le_qNat(z,Y). % 1.88/2.08 0 [] -le_qNat(s(Z),z). % 1.88/2.08 0 [] -le_qNat(s(Z),s(M))|le_qNat(Z,M). % 1.88/2.08 0 [] le_qNat(s(Z),s(M))| -le_qNat(Z,M). % 1.88/2.08 0 [] sorted(nil). % 1.88/2.08 0 [] sorted(cons(Y,nil)). % 1.88/2.08 0 [] -sorted(cons(Y,cons(Y2,Xs)))|le_qNat(Y,Y2). % 1.88/2.08 0 [] -sorted(cons(Y,cons(Y2,Xs)))|sorted(cons(Y2,Xs)). % 1.88/2.08 0 [] sorted(cons(Y,cons(Y2,Xs)))| -le_qNat(Y,Y2)| -sorted(cons(Y2,Xs)). % 1.88/2.08 0 [] lengthNat(nil)=z. % 1.88/2.08 0 [] lengthNat(cons(Y,Xs))=s(lengthNat(Xs)). % 1.88/2.08 0 [] -elemNat(X,nil). % 1.88/2.08 0 [] -elemNat(X,cons(Z,Xs))|X=Z|elemNat(X,Xs). % 1.88/2.08 0 [] elemNat(X,cons(Z,Xs))|X!=Z. % 1.88/2.08 0 [] elemNat(X,cons(Z,Xs))| -elemNat(X,Xs). % 1.88/2.08 0 [] unique(nil). % 1.88/2.08 0 [] -unique(cons(Y,Xs))| -elemNat(Y,Xs). % 1.88/2.08 0 [] -unique(cons(Y,Xs))|unique(Xs). % 1.88/2.08 0 [] unique(cons(Y,Xs))|elemNat(Y,Xs)| -unique(Xs). % 1.88/2.08 0 [] append(nil,Y)=Y. % 1.88/2.08 0 [] append(cons(Z,Xs),Y)=cons(Z,append(Xs,Y)). % 1.88/2.08 0 [] rev(nil)=nil. % 1.88/2.08 0 [] rev(cons(Y,Xs))=append(rev(Xs),cons(Y,nil)). % 1.88/2.08 0 [] -sorted(rev(Xs))| -unique(Xs)|le_qNat(lengthNat(Xs),s(s(s(z)))). % 1.88/2.08 end_of_list. % 1.88/2.08 % 1.88/2.08 SCAN INPUT: prop=0, horn=0, equality=1, symmetry=0, max_lits=3. % 1.88/2.08 % 1.88/2.08 This ia a non-Horn set with equality. The strategy will be % 1.88/2.08 Knuth-Bendix, ordered hyper_res, factoring, and unit % 1.88/2.08 deletion, with positive clauses in sos and nonpositive % 1.88/2.08 clauses in usable. % 1.88/2.08 % 1.88/2.08 dependent: set(knuth_bendix). % 1.88/2.08 dependent: set(anl_eq). % 1.88/2.08 dependent: set(para_from). % 1.88/2.08 dependent: set(para_into). % 1.88/2.08 dependent: clear(para_from_right). % 1.88/2.08 dependent: clear(para_into_right). % 1.88/2.08 dependent: set(para_from_vars). % 1.88/2.08 dependent: set(eq_units_both_ways). % 1.88/2.08 dependent: set(dynamic_demod_all). % 1.88/2.08 dependent: set(dynamic_demod). % 1.88/2.08 dependent: set(order_eq). % 1.88/2.08 dependent: set(back_demod). % 1.88/2.08 dependent: set(lrpo). % 1.88/2.08 dependent: set(hyper_res). % 1.88/2.08 dependent: set(unit_deletion). % 1.88/2.08 dependent: set(factor). % 1.88/2.08 % 1.88/2.08 ------------> process usable: % 1.88/2.08 ** KEPT (pick-wt=5): 2 [copy,1,flip.1] cons(A,B)!=nil. % 1.88/2.08 ** KEPT (pick-wt=4): 4 [copy,3,flip.1] s(A)!=z. % 1.88/2.08 ** KEPT (pick-wt=4): 5 [] -le_qNat(s(A),z). % 1.88/2.08 ** KEPT (pick-wt=8): 6 [] -le_qNat(s(A),s(B))|le_qNat(A,B). % 1.88/2.08 ** KEPT (pick-wt=8): 7 [] le_qNat(s(A),s(B))| -le_qNat(A,B). % 1.88/2.08 ** KEPT (pick-wt=9): 8 [] -sorted(cons(A,cons(B,C)))|le_qNat(A,B). % 1.88/2.08 ** KEPT (pick-wt=10): 9 [] -sorted(cons(A,cons(B,C)))|sorted(cons(B,C)). % 1.88/2.08 ** KEPT (pick-wt=13): 10 [] sorted(cons(A,cons(B,C)))| -le_qNat(A,B)| -sorted(cons(B,C)). % 1.88/2.08 ** KEPT (pick-wt=3): 11 [] -elemNat(A,nil). % 1.88/2.08 ** KEPT (pick-wt=11): 12 [] -elemNat(A,cons(B,C))|A=B|elemNat(A,C). % 1.88/2.08 ** KEPT (pick-wt=8): 13 [] elemNat(A,cons(B,C))|A!=B. % 1.88/2.08 ** KEPT (pick-wt=8): 14 [] elemNat(A,cons(B,C))| -elemNat(A,C). % 12.85/13.04 ** KEPT (pick-wt=7): 15 [] -unique(cons(A,B))| -elemNat(A,B). % 12.85/13.04 ** KEPT (pick-wt=6): 16 [] -unique(cons(A,B))|unique(B). % 12.85/13.04 ** KEPT (pick-wt=9): 17 [] unique(cons(A,B))|elemNat(A,B)| -unique(B). % 12.85/13.04 ** KEPT (pick-wt=12): 18 [] -sorted(rev(A))| -unique(A)|le_qNat(lengthNat(A),s(s(s(z)))). % 12.85/13.04 % 12.85/13.04 ------------> process sos: % 12.85/13.04 ** KEPT (pick-wt=3): 19 [] A=A. % 12.85/13.04 ** KEPT (pick-wt=6): 20 [] head(cons(A,B))=A. % 12.85/13.04 ---> New Demodulator: 21 [new_demod,20] head(cons(A,B))=A. % 12.85/13.04 ** KEPT (pick-wt=6): 22 [] tail(cons(A,B))=B. % 12.85/13.04 ---> New Demodulator: 23 [new_demod,22] tail(cons(A,B))=B. % 12.85/13.04 ** KEPT (pick-wt=5): 24 [] proj1S(s(A))=A. % 12.85/13.04 ---> New Demodulator: 25 [new_demod,24] proj1S(s(A))=A. % 12.85/13.04 ** KEPT (pick-wt=3): 26 [] le_qNat(z,A). % 12.85/13.04 ** KEPT (pick-wt=2): 27 [] sorted(nil). % 12.85/13.04 ** KEPT (pick-wt=4): 28 [] sorted(cons(A,nil)). % 12.85/13.04 ** KEPT (pick-wt=4): 29 [] lengthNat(nil)=z. % 12.85/13.04 ---> New Demodulator: 30 [new_demod,29] lengthNat(nil)=z. % 12.85/13.04 ** KEPT (pick-wt=8): 31 [] lengthNat(cons(A,B))=s(lengthNat(B)). % 12.85/13.04 ** KEPT (pick-wt=2): 32 [] unique(nil). % 12.85/13.04 ** KEPT (pick-wt=5): 33 [] append(nil,A)=A. % 12.85/13.04 ---> New Demodulator: 34 [new_demod,33] append(nil,A)=A. % 12.85/13.04 ** KEPT (pick-wt=11): 36 [copy,35,flip.1] cons(A,append(B,C))=append(cons(A,B),C). % 12.85/13.04 ---> New Demodulator: 37 [new_demod,36] cons(A,append(B,C))=append(cons(A,B),C). % 12.85/13.04 ** KEPT (pick-wt=4): 38 [] rev(nil)=nil. % 12.85/13.04 ---> New Demodulator: 39 [new_demod,38] rev(nil)=nil. % 12.85/13.04 ** KEPT (pick-wt=11): 40 [] rev(cons(A,B))=append(rev(B),cons(A,nil)). % 12.85/13.04 ---> New Demodulator: 41 [new_demod,40] rev(cons(A,B))=append(rev(B),cons(A,nil)). % 12.85/13.04 Following clause subsumed by 19 during input processing: 0 [copy,19,flip.1] A=A. % 12.85/13.04 >>>> Starting back demodulation with 21. % 12.85/13.04 >>>> Starting back demodulation with 23. % 12.85/13.04 >>>> Starting back demodulation with 25. % 12.85/13.04 >>>> Starting back demodulation with 30. % 12.85/13.04 ** KEPT (pick-wt=8): 42 [copy,31,flip.1] s(lengthNat(A))=lengthNat(cons(B,A)). % 12.85/13.04 >>>> Starting back demodulation with 34. % 12.85/13.04 >>>> Starting back demodulation with 37. % 12.85/13.04 >>>> Starting back demodulation with 39. % 12.85/13.04 >>>> Starting back demodulation with 41. % 12.85/13.04 Following clause subsumed by 31 during input processing: 0 [copy,42,flip.1] lengthNat(cons(A,B))=s(lengthNat(B)). % 12.85/13.04 % 12.85/13.04 ======= end of input processing ======= % 12.85/13.04 % 12.85/13.04 =========== start of search =========== % 12.85/13.04 % 12.85/13.04 % 12.85/13.04 Resetting weight limit to 11. % 12.85/13.04 % 12.85/13.04 % 12.85/13.04 Resetting weight limit to 11. % 12.85/13.04 % 12.85/13.04 sos_size=779 % 12.85/13.04 % 12.85/13.04 Search stopped because sos empty. % 12.85/13.04 % 12.85/13.04 % 12.85/13.04 Search stopped because sos empty. % 12.85/13.04 % 12.85/13.04 ============ end of search ============ % 12.85/13.04 % 12.85/13.04 -------------- statistics ------------- % 12.85/13.04 clauses given 906 % 12.85/13.04 clauses generated 300236 % 12.85/13.04 clauses kept 945 % 12.85/13.04 clauses forward subsumed 5338 % 12.85/13.04 clauses back subsumed 26 % 12.85/13.04 Kbytes malloced 6835 % 12.85/13.04 % 12.85/13.04 ----------- times (seconds) ----------- % 12.85/13.04 user CPU time 10.96 (0 hr, 0 min, 10 sec) % 12.85/13.04 system CPU time 0.00 (0 hr, 0 min, 0 sec) % 12.85/13.04 wall-clock time 13 (0 hr, 0 min, 13 sec) % 12.85/13.04 % 12.85/13.04 Process 14728 finished Tue May 5 11:25:53 2026 % 12.85/13.04 Otter interrupted % 12.85/13.04 PROOF NOT FOUND %------------------------------------------------------------------------------