YES Problem 1: Infeasibility Problem: [(VAR vNonEmpty x vNonEmpty) (STRATEGY CONTEXTSENSITIVE (a) (b) (f 1 2) (c) (fSNonEmpty) ) (RULES a -> b b -> a f(x,x) -> c ) ] Infeasibility Conditions: f(a,c) ->* a Problem 1: Obtaining a model using Mace4: -> Usable Rules: a -> b b -> a f(x,x) -> c -> Mace4 Output: ============================== Mace4 ================================= Mace4 (64) version 2009-11A, November 2009. Process 3392693 was started by sandbox2 on z034.star.cs.uiowa.edu, Tue Jul 30 09:59:40 2024 The command was "./mace4 -c -f /tmp/mace43392680-2.in". ============================== end of head =========================== ============================== INPUT ================================= % Reading from file /tmp/mace43392680-2.in assign(max_seconds,100). formulas(assumptions). ->(x1,y) -> ->(f(x1,x2),f(y,x2)) # label(congruence). ->(x2,y) -> ->(f(x1,x2),f(x1,y)) # label(congruence). ->(a,b) # label(replacement). ->(b,a) # label(replacement). ->(f(x1,x1),c) # label(replacement). ->*(x,x) # label(reflexivity). ->(x,y) & ->*(y,z) -> ->*(x,z) # label(transitivity). end_of_list. formulas(goals). ->*(f(a,c),a) # label(goal). end_of_list. ============================== end of input ========================== ============================== PROCESS NON-CLAUSAL FORMULAS ========== % Formulas that are not ordinary clauses: 1 ->(x1,y) -> ->(f(x1,x2),f(y,x2)) # label(congruence) # label(non_clause). [assumption]. 2 ->(x2,y) -> ->(f(x1,x2),f(x1,y)) # label(congruence) # label(non_clause). [assumption]. 3 ->(x,y) & ->*(y,z) -> ->*(x,z) # label(transitivity) # label(non_clause). [assumption]. 4 ->*(f(a,c),a) # label(goal) # label(non_clause) # label(goal). [goal]. ============================== end of process non-clausal formulas === ============================== CLAUSES FOR SEARCH ==================== formulas(mace4_clauses). -->(x,y) | ->(f(x,z),f(y,z)) # label(congruence). -->(x,y) | ->(f(z,x),f(z,y)) # label(congruence). ->(a,b) # label(replacement). ->(b,a) # label(replacement). ->(f(x,x),c) # label(replacement). ->*(x,x) # label(reflexivity). -->(x,y) | -->*(y,z) | ->*(x,z) # label(transitivity). -->*(f(a,c),a) # 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(a, [ 0 ]), function(b, [ 0 ]), function(c, [ 1 ]), function(f(_,_), [ 0, 1, 0, 1 ]), relation(->*(_,_), [ 1, 1, 0, 1 ]), relation(->(_,_), [ 1, 1, 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=31, kept=27. Selections=5, assignments=6, propagations=14, current_models=1. Rewrite_terms=57, rewrite_bools=51, indexes=10. 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 3392693 exit (max_models) Tue Jul 30 09:59:40 2024 The process finished Tue Jul 30 09:59:40 2024 Mace4 cooked interpretation: % number = 1 % seconds = 0 % Interpretation of size 2 a = 0. b = 0. c = 1. f(0,0) = 0. f(0,1) = 1. f(1,0) = 0. f(1,1) = 1. ->*(0,0). ->*(0,1). - ->*(1,0). ->*(1,1). ->(0,0). ->(0,1). - ->(1,0). ->(1,1). The problem is infeasible.