Solving ../../benchmarks/smtlib/true/reverse_not_null.smt2... Inference procedure has parameters: Ice fuel: 200 Timeout: Some(60.) (sec) Teacher_type: Checks all clauses every time Approximation method: remove every clause that can be safely removed Learning problem is: env: { elt -> {a, b} ; eltlist -> {cons, nil} } definition: { (append, F: { append(nil, l2, l2) <= True append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) } eq_eltlist(_nc, _oc) <= append(_lc, _mc, _nc) /\ append(_lc, _mc, _oc) ) (reverse, F: { reverse(nil, nil) <= True reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) } eq_eltlist(_sc, _tc) <= reverse(_rc, _sc) /\ reverse(_rc, _tc) ) (not_null, P: { not_null(cons(x, ll)) <= True False <= not_null(nil) } ) } properties: { not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) } over-approximation: {append, reverse} under-approximation: {} Clause system for inference is: { append(nil, l2, l2) <= True -> 0 not_null(cons(x, ll)) <= True -> 0 reverse(nil, nil) <= True -> 0 reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) -> 0 append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) -> 0 not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) -> 0 False <= not_null(nil) -> 0 } Solving took 0.052802 seconds. Yes: |_ name: None append -> [ append : { append(cons(x_0_0, x_0_1), cons(x_1_0, x_1_1), cons(x_2_0, x_2_1)) <= True append(cons(x_0_0, x_0_1), nil, cons(x_2_0, x_2_1)) <= True append(nil, cons(x_1_0, x_1_1), cons(x_2_0, x_2_1)) <= True append(nil, nil, nil) <= True } ] ; not_null -> [ not_null : { not_null(cons(x_0_0, x_0_1)) <= True } ] ; reverse -> [ reverse : { reverse(cons(x_0_0, x_0_1), cons(x_1_0, x_1_1)) <= True reverse(nil, nil) <= True } ] -- Equality automata are defined for: {elt, eltlist} _| ------------------- STEPS: ------------------------------------------- Step 0, which took 0.010023 s (model generation: 0.009978, model checking: 0.000045): Clauses: { append(nil, l2, l2) <= True -> 0 not_null(cons(x, ll)) <= True -> 0 reverse(nil, nil) <= True -> 0 reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) -> 0 append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) -> 0 not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) -> 0 False <= not_null(nil) -> 0 } Accumulated learning constraints: { } Current best model: |_ name: None append -> [ append : { } ] ; not_null -> [ not_null : { } ] ; reverse -> [ reverse : { } ] -- Equality automata are defined for: {elt, eltlist} _| Answer of teacher: append(nil, l2, l2) <= True : Yes: { l2 -> nil } not_null(cons(x, ll)) <= True : Yes: { } reverse(nil, nil) <= True : Yes: { } reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) : No: () append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) : No: () not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) : No: () False <= not_null(nil) : No: () ------------------------------------------- Step 1, which took 0.009694 s (model generation: 0.009644, model checking: 0.000050): Clauses: { append(nil, l2, l2) <= True -> 0 not_null(cons(x, ll)) <= True -> 0 reverse(nil, nil) <= True -> 0 reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) -> 0 append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) -> 0 not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) -> 0 False <= not_null(nil) -> 0 } Accumulated learning constraints: { append(nil, nil, nil) <= True not_null(cons(a, nil)) <= True reverse(nil, nil) <= True } Current best model: |_ name: None append -> [ append : { append(nil, nil, nil) <= True } ] ; not_null -> [ not_null : { not_null(cons(x_0_0, x_0_1)) <= True } ] ; reverse -> [ reverse : { reverse(nil, nil) <= True } ] -- Equality automata are defined for: {elt, eltlist} _| Answer of teacher: append(nil, l2, l2) <= True : Yes: { l2 -> cons(_yvjca_0, _yvjca_1) } not_null(cons(x, ll)) <= True : No: () reverse(nil, nil) <= True : No: () reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) : No: () append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) : Yes: { _kc -> nil ; l2 -> nil ; t1 -> nil } not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) : No: () False <= not_null(nil) : No: () ------------------------------------------- Step 2, which took 0.013526 s (model generation: 0.013444, model checking: 0.000082): Clauses: { append(nil, l2, l2) <= True -> 0 not_null(cons(x, ll)) <= True -> 0 reverse(nil, nil) <= True -> 0 reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) -> 0 append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) -> 0 not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) -> 0 False <= not_null(nil) -> 0 } Accumulated learning constraints: { append(cons(a, nil), nil, cons(a, nil)) <= True append(nil, cons(a, nil), cons(a, nil)) <= True append(nil, nil, nil) <= True not_null(cons(a, nil)) <= True reverse(nil, nil) <= True } Current best model: |_ name: None append -> [ append : { append(cons(x_0_0, x_0_1), nil, cons(x_2_0, x_2_1)) <= True append(nil, cons(x_1_0, x_1_1), cons(x_2_0, x_2_1)) <= True append(nil, nil, nil) <= True } ] ; not_null -> [ not_null : { not_null(cons(x_0_0, x_0_1)) <= True } ] ; reverse -> [ reverse : { reverse(nil, nil) <= True } ] -- Equality automata are defined for: {elt, eltlist} _| Answer of teacher: append(nil, l2, l2) <= True : No: () not_null(cons(x, ll)) <= True : No: () reverse(nil, nil) <= True : No: () reverse(cons(h1, t1), _qc) <= append(_pc, cons(h1, nil), _qc) /\ reverse(t1, _pc) : Yes: { _pc -> nil ; _qc -> cons(_dwjca_0, _dwjca_1) ; t1 -> nil } append(cons(h1, t1), l2, cons(h1, _kc)) <= append(t1, l2, _kc) : Yes: { _kc -> cons(_fwjca_0, _fwjca_1) ; l2 -> cons(_gwjca_0, _gwjca_1) ; t1 -> nil } not_null(_uc) <= not_null(l1) /\ reverse(l1, _uc) : No: () False <= not_null(nil) : No: () Total time: 0.052802 Learner time: 0.033066 Teacher time: 0.000177 Reasons for stopping: Yes: |_ name: None append -> [ append : { append(cons(x_0_0, x_0_1), cons(x_1_0, x_1_1), cons(x_2_0, x_2_1)) <= True append(cons(x_0_0, x_0_1), nil, cons(x_2_0, x_2_1)) <= True append(nil, cons(x_1_0, x_1_1), cons(x_2_0, x_2_1)) <= True append(nil, nil, nil) <= True } ] ; not_null -> [ not_null : { not_null(cons(x_0_0, x_0_1)) <= True } ] ; reverse -> [ reverse : { reverse(cons(x_0_0, x_0_1), cons(x_1_0, x_1_1)) <= True reverse(nil, nil) <= True } ] -- Equality automata are defined for: {elt, eltlist} _|