NO Problem 1: Infeasibility Problem: [(VAR vNonEmpty x y l vNonEmpty x1 x2) (STRATEGY CONTEXTSENSITIVE (le 1 2) (min 1) (0) (cons 1 2) (fSNonEmpty) (false) (nil) (s 1) (true) ) (RULES le(0,s(x)) -> true le(s(x),s(y)) -> le(x,y) le(x,0) -> false min(cons(x,nil)) -> x min(cons(x,l)) -> min(l) | le(x,min(l)) ->* false min(cons(x,l)) -> min(l) | min(l) ->* x min(cons(x,l)) -> x | le(x,min(l)) ->* true ) ] Infeasibility Conditions: le(x1,min(x2)) ->* false, min(x2) ->* x1 Problem 1: Obtaining a proof using Prover9: -> Prover9 Output: ============================== Prover9 =============================== Prover9 (64) version 2009-11A, November 2009. Process 3262623 was started by sandbox2 on z024.star.cs.uiowa.edu, Tue Jul 30 08:51:40 2024 The command was "./prover9 -f /tmp/prover93262616-0.in". ============================== end of head =========================== ============================== INPUT ================================= % Reading from file /tmp/prover93262616-0.in assign(max_seconds,20). formulas(assumptions). ->_s0(x1,y) -> ->_s0(le(x1,x2),le(y,x2)) # label(congruence). ->_s0(x2,y) -> ->_s0(le(x1,x2),le(x1,y)) # label(congruence). ->_s0(x1,y) -> ->_s0(min(x1),min(y)) # label(congruence). ->_s0(x1,y) -> ->_s0(cons(x1,x2),cons(y,x2)) # label(congruence). ->_s0(x2,y) -> ->_s0(cons(x1,x2),cons(x1,y)) # label(congruence). ->_s0(x1,y) -> ->_s0(s(x1),s(y)) # label(congruence). ->_s0(le(0,s(x1)),true) # label(replacement). ->_s0(le(s(x1),s(x2)),le(x1,x2)) # label(replacement). ->_s0(le(x1,0),false) # label(replacement). ->_s0(min(cons(x1,nil)),x1) # label(replacement). ->*_s0(le(x1,min(x3)),false) -> ->_s0(min(cons(x1,x3)),min(x3)) # label(replacement). ->*_s0(min(x3),x1) -> ->_s0(min(cons(x1,x3)),min(x3)) # label(replacement). ->*_s0(le(x1,min(x3)),true) -> ->_s0(min(cons(x1,x3)),x1) # label(replacement). ->*_s0(x,x) # label(reflexivity). ->_s0(x,y) & ->*_s0(y,z) -> ->*_s0(x,z) # label(transitivity). end_of_list. formulas(goals). (exists x5 exists x6 (->*_s0(le(x5,min(x6)),false) & ->*_s0(min(x6),x5))) # label(goal). end_of_list. ============================== end of input ========================== ============================== PROCESS NON-CLAUSAL FORMULAS ========== % Formulas that are not ordinary clauses: 1 ->_s0(x1,y) -> ->_s0(le(x1,x2),le(y,x2)) # label(congruence) # label(non_clause). [assumption]. 2 ->_s0(x2,y) -> ->_s0(le(x1,x2),le(x1,y)) # label(congruence) # label(non_clause). [assumption]. 3 ->_s0(x1,y) -> ->_s0(min(x1),min(y)) # label(congruence) # label(non_clause). [assumption]. 4 ->_s0(x1,y) -> ->_s0(cons(x1,x2),cons(y,x2)) # label(congruence) # label(non_clause). [assumption]. 5 ->_s0(x2,y) -> ->_s0(cons(x1,x2),cons(x1,y)) # label(congruence) # label(non_clause). [assumption]. 6 ->_s0(x1,y) -> ->_s0(s(x1),s(y)) # label(congruence) # label(non_clause). [assumption]. 7 ->*_s0(le(x1,min(x3)),false) -> ->_s0(min(cons(x1,x3)),min(x3)) # label(replacement) # label(non_clause). [assumption]. 8 ->*_s0(min(x3),x1) -> ->_s0(min(cons(x1,x3)),min(x3)) # label(replacement) # label(non_clause). [assumption]. 9 ->*_s0(le(x1,min(x3)),true) -> ->_s0(min(cons(x1,x3)),x1) # label(replacement) # label(non_clause). [assumption]. 10 ->_s0(x,y) & ->*_s0(y,z) -> ->*_s0(x,z) # label(transitivity) # label(non_clause). [assumption]. 11 (exists x5 exists x6 (->*_s0(le(x5,min(x6)),false) & ->*_s0(min(x6),x5))) # label(goal) # label(non_clause) # label(goal). [goal]. ============================== end of process non-clausal formulas === ============================== PROCESS INITIAL CLAUSES =============== % Clauses before input processing: formulas(usable). end_of_list. formulas(sos). -->_s0(x,y) | ->_s0(le(x,z),le(y,z)) # label(congruence). [clausify(1)]. -->_s0(x,y) | ->_s0(le(z,x),le(z,y)) # label(congruence). [clausify(2)]. -->_s0(x,y) | ->_s0(min(x),min(y)) # label(congruence). [clausify(3)]. -->_s0(x,y) | ->_s0(cons(x,z),cons(y,z)) # label(congruence). [clausify(4)]. -->_s0(x,y) | ->_s0(cons(z,x),cons(z,y)) # label(congruence). [clausify(5)]. -->_s0(x,y) | ->_s0(s(x),s(y)) # label(congruence). [clausify(6)]. ->_s0(le(0,s(x)),true) # label(replacement). [assumption]. ->_s0(le(s(x),s(y)),le(x,y)) # label(replacement). [assumption]. ->_s0(le(x,0),false) # label(replacement). [assumption]. ->_s0(min(cons(x,nil)),x) # label(replacement). [assumption]. -->*_s0(le(x,min(y)),false) | ->_s0(min(cons(x,y)),min(y)) # label(replacement). [clausify(7)]. -->*_s0(min(x),y) | ->_s0(min(cons(y,x)),min(x)) # label(replacement). [clausify(8)]. -->*_s0(le(x,min(y)),true) | ->_s0(min(cons(x,y)),x) # label(replacement). [clausify(9)]. ->*_s0(x,x) # label(reflexivity). [assumption]. -->_s0(x,y) | -->*_s0(y,z) | ->*_s0(x,z) # label(transitivity). [clausify(10)]. -->*_s0(le(x,min(y)),false) | -->*_s0(min(y),x) # label(goal). [deny(11)]. end_of_list. formulas(demodulators). end_of_list. ============================== PREDICATE ELIMINATION ================= No predicates eliminated. ============================== end predicate elimination ============= Auto_denials: % copying label goal to answer in negative clause Term ordering decisions: Predicate symbol precedence: predicate_order([ ->_s0, ->*_s0 ]). Function symbol precedence: function_order([ true, 0, false, nil, le, cons, min, s ]). After inverse_order: (no changes). Unfolding symbols: (none). Auto_inference settings: % set(neg_binary_resolution). % (HNE depth_diff=-7) % clear(ordered_res). % (HNE depth_diff=-7) % set(ur_resolution). % (HNE depth_diff=-7) % set(ur_resolution) -> set(pos_ur_resolution). % set(ur_resolution) -> set(neg_ur_resolution). Auto_process settings: % set(unit_deletion). % (Horn set with negative nonunits) kept: 12 -->_s0(x,y) | ->_s0(le(x,z),le(y,z)) # label(congruence). [clausify(1)]. kept: 13 -->_s0(x,y) | ->_s0(le(z,x),le(z,y)) # label(congruence). [clausify(2)]. kept: 14 -->_s0(x,y) | ->_s0(min(x),min(y)) # label(congruence). [clausify(3)]. kept: 15 -->_s0(x,y) | ->_s0(cons(x,z),cons(y,z)) # label(congruence). [clausify(4)]. kept: 16 -->_s0(x,y) | ->_s0(cons(z,x),cons(z,y)) # label(congruence). [clausify(5)]. kept: 17 -->_s0(x,y) | ->_s0(s(x),s(y)) # label(congruence). [clausify(6)]. kept: 18 ->_s0(le(0,s(x)),true) # label(replacement). [assumption]. kept: 19 ->_s0(le(s(x),s(y)),le(x,y)) # label(replacement). [assumption]. kept: 20 ->_s0(le(x,0),false) # label(replacement). [assumption]. kept: 21 ->_s0(min(cons(x,nil)),x) # label(replacement). [assumption]. kept: 22 -->*_s0(le(x,min(y)),false) | ->_s0(min(cons(x,y)),min(y)) # label(replacement). [clausify(7)]. kept: 23 -->*_s0(min(x),y) | ->_s0(min(cons(y,x)),min(x)) # label(replacement). [clausify(8)]. kept: 24 -->*_s0(le(x,min(y)),true) | ->_s0(min(cons(x,y)),x) # label(replacement). [clausify(9)]. kept: 25 ->*_s0(x,x) # label(reflexivity). [assumption]. kept: 26 -->_s0(x,y) | -->*_s0(y,z) | ->*_s0(x,z) # label(transitivity). [clausify(10)]. kept: 27 -->*_s0(le(x,min(y)),false) | -->*_s0(min(y),x) # label(goal) # answer(goal). [deny(11)]. ============================== end of process initial clauses ======== ============================== CLAUSES FOR SEARCH ==================== % Clauses after input processing: formulas(usable). end_of_list. formulas(sos). 12 -->_s0(x,y) | ->_s0(le(x,z),le(y,z)) # label(congruence). [clausify(1)]. 13 -->_s0(x,y) | ->_s0(le(z,x),le(z,y)) # label(congruence). [clausify(2)]. 14 -->_s0(x,y) | ->_s0(min(x),min(y)) # label(congruence). [clausify(3)]. 15 -->_s0(x,y) | ->_s0(cons(x,z),cons(y,z)) # label(congruence). [clausify(4)]. 16 -->_s0(x,y) | ->_s0(cons(z,x),cons(z,y)) # label(congruence). [clausify(5)]. 17 -->_s0(x,y) | ->_s0(s(x),s(y)) # label(congruence). [clausify(6)]. 18 ->_s0(le(0,s(x)),true) # label(replacement). [assumption]. 19 ->_s0(le(s(x),s(y)),le(x,y)) # label(replacement). [assumption]. 20 ->_s0(le(x,0),false) # label(replacement). [assumption]. 21 ->_s0(min(cons(x,nil)),x) # label(replacement). [assumption]. 22 -->*_s0(le(x,min(y)),false) | ->_s0(min(cons(x,y)),min(y)) # label(replacement). [clausify(7)]. 23 -->*_s0(min(x),y) | ->_s0(min(cons(y,x)),min(x)) # label(replacement). [clausify(8)]. 24 -->*_s0(le(x,min(y)),true) | ->_s0(min(cons(x,y)),x) # label(replacement). [clausify(9)]. 25 ->*_s0(x,x) # label(reflexivity). [assumption]. 26 -->_s0(x,y) | -->*_s0(y,z) | ->*_s0(x,z) # label(transitivity). [clausify(10)]. 27 -->*_s0(le(x,min(y)),false) | -->*_s0(min(y),x) # label(goal) # answer(goal). [deny(11)]. end_of_list. formulas(demodulators). end_of_list. ============================== end of clauses for search ============= ============================== SEARCH ================================ % Starting search at 0.01 seconds. given #1 (I,wt=10): 12 -->_s0(x,y) | ->_s0(le(x,z),le(y,z)) # label(congruence). [clausify(1)]. given #2 (I,wt=10): 13 -->_s0(x,y) | ->_s0(le(z,x),le(z,y)) # label(congruence). [clausify(2)]. given #3 (I,wt=8): 14 -->_s0(x,y) | ->_s0(min(x),min(y)) # label(congruence). [clausify(3)]. given #4 (I,wt=10): 15 -->_s0(x,y) | ->_s0(cons(x,z),cons(y,z)) # label(congruence). [clausify(4)]. given #5 (I,wt=10): 16 -->_s0(x,y) | ->_s0(cons(z,x),cons(z,y)) # label(congruence). [clausify(5)]. given #6 (I,wt=8): 17 -->_s0(x,y) | ->_s0(s(x),s(y)) # label(congruence). [clausify(6)]. given #7 (I,wt=6): 18 ->_s0(le(0,s(x)),true) # label(replacement). [assumption]. given #8 (I,wt=9): 19 ->_s0(le(s(x),s(y)),le(x,y)) # label(replacement). [assumption]. given #9 (I,wt=5): 20 ->_s0(le(x,0),false) # label(replacement). [assumption]. given #10 (I,wt=6): 21 ->_s0(min(cons(x,nil)),x) # label(replacement). [assumption]. given #11 (I,wt=13): 22 -->*_s0(le(x,min(y)),false) | ->_s0(min(cons(x,y)),min(y)) # label(replacement). [clausify(7)]. given #12 (I,wt=11): 23 -->*_s0(min(x),y) | ->_s0(min(cons(y,x)),min(x)) # label(replacement). [clausify(8)]. given #13 (I,wt=12): 24 -->*_s0(le(x,min(y)),true) | ->_s0(min(cons(x,y)),x) # label(replacement). [clausify(9)]. given #14 (I,wt=3): 25 ->*_s0(x,x) # label(reflexivity). [assumption]. given #15 (I,wt=9): 26 -->_s0(x,y) | -->*_s0(y,z) | ->*_s0(x,z) # label(transitivity). [clausify(10)]. given #16 (I,wt=10): 27 -->*_s0(le(x,min(y)),false) | -->*_s0(min(y),x) # label(goal) # answer(goal). [deny(11)]. given #17 (A,wt=8): 28 ->_s0(s(le(0,s(x))),s(true)). [ur(17,a,18,a)]. given #18 (F,wt=7): 59 -->*_s0(le(min(x),min(x)),false) # answer(goal). [resolve(27,b,25,a)]. given #19 (F,wt=7): 68 -->_s0(le(min(x),min(x)),false) # answer(goal). [ur(26,b,25,a,c,59,a)]. given #20 (F,wt=10): 67 -->_s0(le(min(x),min(x)),y) | -->*_s0(y,false) # answer(goal). [resolve(59,a,26,c)]. given #21 (F,wt=10): 69 -->*_s0(le(min(x),y),false) | -->_s0(min(x),y) # answer(goal). [resolve(67,a,13,b)]. ============================== PROOF ================================= % Proof 1 at 0.01 (+ 0.00) seconds: goal. % Length of proof is 15. % Level of proof is 6. % Maximum clause weight is 10.000. % Given clauses 21. 2 ->_s0(x2,y) -> ->_s0(le(x1,x2),le(x1,y)) # label(congruence) # label(non_clause). [assumption]. 10 ->_s0(x,y) & ->*_s0(y,z) -> ->*_s0(x,z) # label(transitivity) # label(non_clause). [assumption]. 11 (exists x5 exists x6 (->*_s0(le(x5,min(x6)),false) & ->*_s0(min(x6),x5))) # label(goal) # label(non_clause) # label(goal). [goal]. 13 -->_s0(x,y) | ->_s0(le(z,x),le(z,y)) # label(congruence). [clausify(2)]. 20 ->_s0(le(x,0),false) # label(replacement). [assumption]. 21 ->_s0(min(cons(x,nil)),x) # label(replacement). [assumption]. 25 ->*_s0(x,x) # label(reflexivity). [assumption]. 26 -->_s0(x,y) | -->*_s0(y,z) | ->*_s0(x,z) # label(transitivity). [clausify(10)]. 27 -->*_s0(le(x,min(y)),false) | -->*_s0(min(y),x) # label(goal) # answer(goal). [deny(11)]. 54 ->*_s0(le(x,0),false). [ur(26,a,20,a,b,25,a)]. 59 -->*_s0(le(min(x),min(x)),false) # answer(goal). [resolve(27,b,25,a)]. 67 -->_s0(le(min(x),min(x)),y) | -->*_s0(y,false) # answer(goal). [resolve(59,a,26,c)]. 69 -->*_s0(le(min(x),y),false) | -->_s0(min(x),y) # answer(goal). [resolve(67,a,13,b)]. 76 -->*_s0(le(min(cons(x,nil)),x),false) # answer(goal). [resolve(69,b,21,a)]. 77 $F # answer(goal). [resolve(76,a,54,a)]. ============================== end of proof ========================== ============================== STATISTICS ============================ Given=21. Generated=68. Kept=65. proofs=1. Usable=21. Sos=39. Demods=0. Limbo=4, Disabled=16. Hints=0. Kept_by_rule=0, Deleted_by_rule=0. Forward_subsumed=3. Back_subsumed=0. Sos_limit_deleted=0. Sos_displaced=0. Sos_removed=0. New_demodulators=0 (0 lex), Back_demodulated=0. Back_unit_deleted=0. Demod_attempts=0. Demod_rewrites=0. Res_instance_prunes=0. Para_instance_prunes=0. Basic_paramod_prunes=0. Nonunit_fsub_feature_tests=19. Nonunit_bsub_feature_tests=43. Megabytes=0.18. User_CPU=0.01, System_CPU=0.00, Wall_clock=0. ============================== end of statistics ===================== ============================== end of search ========================= THEOREM PROVED Exiting with 1 proof. Process 3262623 exit (max_proofs) Tue Jul 30 08:51:40 2024 The problem is feasible.