YES Problem 1: Infeasibility Problem: [(VAR vNonEmpty x vNonEmpty) (STRATEGY CONTEXTSENSITIVE (p 1) (pos 1) (s 1) (0) (fSNonEmpty) (false) (true) ) (RULES p(s(x)) -> x pos(p(x)) -> false | pos(x) ->* false pos(s(0)) -> true pos(s(x)) -> true | pos(x) ->* true pos(0) -> false s(p(x)) -> x ) ] Infeasibility Conditions: pos(0) ->* true Problem 1: Obtaining a model using Mace4: -> Usable Rules: pos(p(x)) -> false | pos(x) ->* false pos(s(0)) -> true pos(s(x)) -> true | pos(x) ->* true pos(0) -> false -> Mace4 Output: ============================== Mace4 ================================= Mace4 (64) version 2009-11A, November 2009. Process 3189351 was started by sandbox on z022.star.cs.uiowa.edu, Tue Jul 30 08:37:40 2024 The command was "./mace4 -c -f /tmp/mace43189338-2.in". ============================== end of head =========================== ============================== INPUT ================================= % Reading from file /tmp/mace43189338-2.in assign(max_seconds,100). formulas(assumptions). ->(x1,y) -> ->(p(x1),p(y)) # label(congruence). ->(x1,y) -> ->(pos(x1),pos(y)) # label(congruence). ->(x1,y) -> ->(s(x1),s(y)) # label(congruence). ->*(pos(x1),false) -> ->(pos(p(x1)),false) # label(replacement). ->(pos(s(0)),true) # label(replacement). ->*(pos(x1),true) -> ->(pos(s(x1)),true) # label(replacement). ->(pos(0),false) # label(replacement). ->*(x,x) # label(reflexivity). ->(x,y) & ->*(y,z) -> ->*(x,z) # label(transitivity). end_of_list. formulas(goals). ->*(pos(0),true) # label(goal). end_of_list. ============================== end of input ========================== ============================== PROCESS NON-CLAUSAL FORMULAS ========== % Formulas that are not ordinary clauses: 1 ->(x1,y) -> ->(p(x1),p(y)) # label(congruence) # label(non_clause). [assumption]. 2 ->(x1,y) -> ->(pos(x1),pos(y)) # label(congruence) # label(non_clause). [assumption]. 3 ->(x1,y) -> ->(s(x1),s(y)) # label(congruence) # label(non_clause). [assumption]. 4 ->*(pos(x1),false) -> ->(pos(p(x1)),false) # label(replacement) # label(non_clause). [assumption]. 5 ->*(pos(x1),true) -> ->(pos(s(x1)),true) # label(replacement) # label(non_clause). [assumption]. 6 ->(x,y) & ->*(y,z) -> ->*(x,z) # label(transitivity) # label(non_clause). [assumption]. 7 ->*(pos(0),true) # label(goal) # label(non_clause) # label(goal). [goal]. ============================== end of process non-clausal formulas === ============================== CLAUSES FOR SEARCH ==================== formulas(mace4_clauses). -->(x,y) | ->(p(x),p(y)) # label(congruence). -->(x,y) | ->(pos(x),pos(y)) # label(congruence). -->(x,y) | ->(s(x),s(y)) # label(congruence). -->*(pos(x),false) | ->(pos(p(x)),false) # label(replacement). ->(pos(s(0)),true) # label(replacement). -->*(pos(x),true) | ->(pos(s(x)),true) # label(replacement). ->(pos(0),false) # label(replacement). ->*(x,x) # label(reflexivity). -->(x,y) | -->*(y,z) | ->*(x,z) # label(transitivity). -->*(pos(0),true) # label(goal). end_of_list. ============================== end of clauses for search ============= % There are no natural numbers in the input. ============================== DOMAIN SIZE 2 ========================= ============================== MODEL ================================= interpretation( 2, [number=1, seconds=0], [ function(0, [ 0 ]), function(false, [ 0 ]), function(true, [ 1 ]), function(p(_), [ 0, 0 ]), function(pos(_), [ 0, 1 ]), function(s(_), [ 1, 1 ]), relation(->*(_,_), [ 1, 0, 0, 1 ]), relation(->(_,_), [ 1, 0, 0, 1 ]) ]). ============================== end of model ========================== ============================== STATISTICS ============================ For domain size 2. Current CPU time: 0.00 seconds (total CPU time: 0.00 seconds). Ground clauses: seen=29, kept=25. Selections=8, assignments=11, propagations=12, current_models=1. Rewrite_terms=72, rewrite_bools=46, indexes=13. Rules_from_neg_clauses=3, cross_offs=3. ============================== end of statistics ===================== User_CPU=0.00, System_CPU=0.00, Wall_clock=0. Exiting with 1 model. Process 3189351 exit (max_models) Tue Jul 30 08:37:40 2024 The process finished Tue Jul 30 08:37:40 2024 Mace4 cooked interpretation: % number = 1 % seconds = 0 % Interpretation of size 2 0 = 0. false = 0. true = 1. p(0) = 0. p(1) = 0. pos(0) = 0. pos(1) = 1. s(0) = 1. s(1) = 1. ->*(0,0). - ->*(0,1). - ->*(1,0). ->*(1,1). ->(0,0). - ->(0,1). - ->(1,0). ->(1,1). The problem is infeasible.