Starting on goal: Prolog$Goal(car=l("[]", Prolog$Var(id=0L, instance=r3), "=", l("[]", "a", "|", "false"))) Goal arity 3: "[]"($x, "=", "[]"(a, "|", false)) nextSolution Goal: "[]"($x, "=", "[]"(a, "|", false)). Got clause: "[]"(_7, "=", "[]"(_8, "|", _9)) :- "[]"(_10, "=", new, collector); "[]"("[]"(forall_impl, "()"("[]"(_8, ",", _11, ",", _10))), or, true); "[]"(_7, "=", retrieve, "()"(_10)) Clause unifies to: "[]"($x, "=", "[]"(a, "|", false)) :- "[]"(_10, "=", new, collector); "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", _10))), or, true); "[]"($x, "=", retrieve, "()"(_10)) gdash: "[]"(_10, "=", new, collector); "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", _10))), or, true); "[]"($x, "=", retrieve, "()"(_10)) Goal arity 4: "[]"(_10, "=", new, collector) New goal: "[]"(_10, "=", new, collector); "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", _10))), or, true); "[]"($x, "=", retrieve, "()"(_10)) Goal: "[]"(_10, "=", new, collector); "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", _10))), or, true); "[]"($x, "=", retrieve, "()"(_10)). Got clause: "[]"(_12, "=", new, collector) :- native Clause unifies to: "[]"(_10, "=", new, collector) :- native Clause is native. gdash: "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))), or, true); "[]"($x, "=", retrieve, "()"(___)) Goal arity 3: "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))), or, true) New goal: "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))), or, true); "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))), or, true); "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_27, or, _28) :- _27 Clause unifies to: "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))), or, true) :- "[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))) gdash: "[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))); "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))) New goal: "[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))); "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))); "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(forall_impl, "()"("[]"(_35, ",", _36, ",", _37))) :- _36; "[]"(saveTo, "()"("[]"(_35, ",", _37))); false Clause unifies to: "[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))) :- _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false gdash: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Weird: Goal is variable: _11 New goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: true Clause unifies to: true gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_38, ",", _39))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_52, "=", new, collector) :- native Clause unifies to: "[]"(_52, "=", new, collector) :- native Clause is native. gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_53, ",", _54))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_67, ",", _68))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(_67, ",", _68))) :- native Clause is native. Exception in native: java.lang.ClassCastException: main$Prolog$Var cannot be cast to main$Prolog$Collector Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_69, "=", _70, "()"(_71)) :- native Clause unifies to: "[]"(_69, "=", _70, "()"(_71)) :- native Clause is native. Exception in native: java.lang.ClassCastException: main$Prolog$Var cannot be cast to main$Prolog$Collector Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: nativeTest2 :- native Clause unifies to: nativeTest2 :- native Clause is native. gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_72, ",", _73))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: nativeFail :- native Clause unifies to: nativeFail :- native Clause is native. Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_86, "=", intmul, "()"("[]"(_87, ",", _88))) :- native Clause unifies to: "[]"(_86, "=", intmul, "()"("[]"(_87, ",", _88))) :- native Clause is native. Exception in native: java.lang.NumberFormatException: For input string: "___" Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_89, "=", intdiv, "()"("[]"(_90, ",", _91))) :- native Clause unifies to: "[]"(_89, "=", intdiv, "()"("[]"(_90, ",", _91))) :- native Clause is native. Exception in native: java.lang.NumberFormatException: For input string: "___" Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_92, "=", intadd, "()"("[]"(_93, ",", _94))) :- native Clause unifies to: "[]"(_92, "=", intadd, "()"("[]"(_93, ",", _94))) :- native Clause is native. Exception in native: java.lang.NumberFormatException: For input string: "___" Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_95, "=", intminus, "()"("[]"(_96, ",", _97))) :- native Clause unifies to: "[]"(_95, "=", intminus, "()"("[]"(_96, ",", _97))) :- native Clause is native. Exception in native: java.lang.NumberFormatException: For input string: "___" Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_98, is, greater, than, _99) :- native Clause unifies to: "[]"(_98, is, greater, than, _99) :- native Clause is native. Exception in native: java.lang.NumberFormatException: For input string: "___" Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(head, _100, exists, in, theory, _101) :- native Clause unifies to: "[]"(head, _100, exists, in, theory, _101) :- native Clause is native. Exception in native: java.lang.NullPointerException Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_102, "=", all, theory, names) :- native Clause unifies to: "[]"(_102, "=", all, theory, names) :- native Clause is native. gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_103, ",", _104))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_117, "=", tocons, "()"(_118)) :- native Clause unifies to: "[]"(_117, "=", tocons, "()"(_118)) :- native Clause is native. gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_119, ",", _120))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_133, is, less, than, _134) :- native Clause unifies to: "[]"(_133, is, less, than, _134) :- native Clause is native. Exception in native: java.lang.NumberFormatException: For input string: "___" Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_135, "=", arg, _136, in, _137) :- native Clause unifies to: "[]"(_135, "=", arg, _136, in, _137) :- native Clause is native. Exception in native: java.lang.NumberFormatException: For input string: "___" Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_138, "=", arity, of, _139) :- native Clause unifies to: "[]"(_138, "=", arity, of, _139) :- native Clause is native. gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_140, ",", _141))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_154, "=", operator, "()"(_155)) :- native Clause unifies to: "[]"(_154, "=", operator, "()"(_155)) :- native Clause is native. gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_156, ",", _157))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(isQuoted, "()"(_170)) :- native Clause unifies to: "[]"(isQuoted, "()"(_170)) :- native Clause is native. Native clause fails Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"("[]"(not, "()"(true)), should, be, false) Clause unifies to: "[]"("[]"(not, "()"(true)), should, be, false) gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_171, ",", _172))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(mrshutco, is, a, human) Clause unifies to: "[]"(mrshutco, is, a, human) gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_185, ",", _186))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"("[]"(not, "()"(false)), should, be, true) Clause unifies to: "[]"("[]"(not, "()"(false)), should, be, true) gdash: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 2: "[]"(saveTo, "()"("[]"(a, ",", ___))) New goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(saveTo, "()"("[]"(_199, ",", _200))) :- native Clause unifies to: "[]"(saveTo, "()"("[]"(a, ",", ___))) :- native Clause is native. gdash: false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: false New goal: false; "[]"($x, "=", retrieve, "()"(___)) Goal: _11; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(not, "()"(_213)) :- _213; "!"; false Clause unifies to: "[]"(not, "()"(_213)) :- _213; "!"; false gdash: _213; "!"("5"); false; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Weird: Goal is variable: _213 New goal: _213; "!"("5"); false; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal: _213; "!"("5"); false; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)). Got clause: true Clause unifies to: true gdash: "!"("5"); false; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) Goal arity 1: "!"("5") New goal: "!"("5"); false; "[]"(saveTo, "()"("[]"(a, ",", ___))); false; "[]"($x, "=", retrieve, "()"(___)) cut -1. Prolog$Goal(car=l("!", "5"), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", "saveTo", l("()", l("[]", Prolog$Var(id=35L, instance=Prolog$Var(id=8L, instance=l("a"))), ",", Prolog$Var(id=37L, instance=Prolog$Var(id=10L, instance=Prolog$Collector(solutions=[r11, r11, r11, r11, r11, r11, r11, r11, r11, r11])))))), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", Prolog$Var(id=7L, instance=Prolog$Var(id=0L, instance=r21)), "=", "retrieve", l("()", r13))))))) Goal arity 0: false cut 0. Prolog$Goal(car=l("!", "5"), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", "saveTo", l("()", l("[]", Prolog$Var(id=35L, instance=Prolog$Var(id=8L, instance=l("a"))), ",", Prolog$Var(id=37L, instance=Prolog$Var(id=10L, instance=Prolog$Collector(solutions=[r11, r11, r11, r11, r11, r11, r11, r11, r11, r11])))))), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", Prolog$Var(id=7L, instance=Prolog$Var(id=0L, instance=r21)), "=", "retrieve", l("()", r13))))))) back to cut point 5 cut: dropping Prolog$Goal(car=l("!", "5"), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", "saveTo", l("()", l("[]", Prolog$Var(id=35L, instance=Prolog$Var(id=8L, instance=l("a"))), ",", Prolog$Var(id=37L, instance=Prolog$Var(id=10L, instance=Prolog$Collector(solutions=[r11, r11, r11, r11, r11, r11, r11, r11, r11, r11])))))), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", Prolog$Var(id=7L, instance=Prolog$Var(id=0L, instance=r21)), "=", "retrieve", l("()", r13))))))) cut: dropping Prolog$Goal(car=Prolog$Var(id=213L, instance=l("true")), cdr=Prolog$Goal(car=l("!", "5"), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", "saveTo", l("()", l("[]", Prolog$Var(id=35L, instance=Prolog$Var(id=8L, instance=l("a"))), ",", Prolog$Var(id=37L, instance=Prolog$Var(id=10L, instance=Prolog$Collector(solutions=[r14, r14, r14, r14, r14, r14, r14, r14, r14, r14])))))), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", Prolog$Var(id=7L, instance=Prolog$Var(id=0L, instance=r24)), "=", "retrieve", l("()", r16)))))))) cut: dropping Prolog$Goal(car=Prolog$Var(id=36L, instance=Prolog$Var(id=11L, instance=l("[]", "not", l("()", Prolog$Var(id=213L, instance=r6))))), cdr=Prolog$Goal(car=l("[]", "saveTo", l("()", l("[]", Prolog$Var(id=35L, instance=Prolog$Var(id=8L, instance=l("a"))), ",", Prolog$Var(id=37L, instance=Prolog$Var(id=10L, instance=Prolog$Collector(solutions=[r13, r13, r13, r13, r13, r13, r13, r13, r13, r13])))))), cdr=Prolog$Goal(car=l("false"), cdr=Prolog$Goal(car=l("[]", Prolog$Var(id=7L, instance=Prolog$Var(id=0L, instance=r23)), "=", "retrieve", l("()", r15)))))) Goal: "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))), or, true); "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_219, or, _220) :- _220 Clause unifies to: "[]"("[]"(forall_impl, "()"("[]"(a, ",", _11, ",", ___))), or, true) :- true gdash: true; "[]"($x, "=", retrieve, "()"(___)) Goal arity 0: true New goal: true; "[]"($x, "=", retrieve, "()"(___)) Goal: true; "[]"($x, "=", retrieve, "()"(___)). Got clause: true Clause unifies to: true gdash: "[]"($x, "=", retrieve, "()"(___)) Goal arity 4: "[]"($x, "=", retrieve, "()"(___)) New goal: "[]"($x, "=", retrieve, "()"(___)) Goal: "[]"($x, "=", retrieve, "()"(___)). Got clause: "[]"(_222, "=", _223, "()"(_224)) :- native Clause unifies to: "[]"($x, "=", retrieve, "()"(___)) :- native Clause is native. gdash: null SUCCESS! solution found in step 225 nextSolution Done with goal! No solution