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remove deprecated API functionality

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2015-11-14 13:47:41 -08:00
parent c2108f74f1
commit 0f602d652a
13 changed files with 368 additions and 1772 deletions
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98
examples/maxsat/maxsat.c
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@ -163,11 +163,11 @@ void free_cnstr_array(Z3_ast * cnstrs)
/**
\brief Assert hard constraints stored in the given array.
*/
void assert_hard_constraints(Z3_context ctx, unsigned num_cnstrs, Z3_ast * cnstrs)
void assert_hard_constraints(Z3_context ctx, Z3_solver s, unsigned num_cnstrs, Z3_ast * cnstrs)
{
unsigned i;
for (i = 0; i < num_cnstrs; i++) {
Z3_assert_cnstr(ctx, cnstrs[i]);
Z3_solver_assert(ctx, s, cnstrs[i]);
}
}
@ -176,14 +176,14 @@ void assert_hard_constraints(Z3_context ctx, unsigned num_cnstrs, Z3_ast * cnstr
This funtion will assert each soft-constraint C_i as (C_i or k_i) where k_i is a fresh boolean variable.
It will also return an array containing these fresh variables.
*/
Z3_ast * assert_soft_constraints(Z3_context ctx, unsigned num_cnstrs, Z3_ast * cnstrs)
Z3_ast * assert_soft_constraints(Z3_context ctx, Z3_solver s, unsigned num_cnstrs, Z3_ast * cnstrs)
{
unsigned i;
Z3_ast * aux_vars;
aux_vars = mk_fresh_bool_var_array(ctx, num_cnstrs);
for (i = 0; i < num_cnstrs; i++) {
Z3_ast assumption = cnstrs[i];
Z3_assert_cnstr(ctx, mk_binary_or(ctx, assumption, aux_vars[i]));
Z3_solver_assert(ctx, s, mk_binary_or(ctx, assumption, aux_vars[i]));
}
return aux_vars;
}
@ -299,7 +299,7 @@ int get_bit(unsigned val, unsigned idx)
/**
\brief Given an integer val encoded in n bits (boolean variables), assert the constraint that val <= k.
*/
void assert_le_k(Z3_context ctx, unsigned n, Z3_ast * val, unsigned k)
void assert_le_k(Z3_context ctx, Z3_solver s, unsigned n, Z3_ast * val, unsigned k)
{
Z3_ast i1, i2, not_val, out;
unsigned idx;
@ -321,7 +321,7 @@ void assert_le_k(Z3_context ctx, unsigned n, Z3_ast * val, unsigned k)
out = mk_ternary_or(ctx, i1, i2, mk_binary_and(ctx, not_val, out));
}
// printf("at-most-k:\n%s\n", Z3_ast_to_string(ctx, out));
Z3_assert_cnstr(ctx, out);
Z3_solver_assert(ctx, s, out);
}
/**
@ -331,14 +331,14 @@ void assert_le_k(Z3_context ctx, unsigned n, Z3_ast * val, unsigned k)
We use a simple encoding using an adder (counter).
An interesting exercise consists in implementing more sophisticated encodings.
*/
void assert_at_most_k(Z3_context ctx, unsigned n, Z3_ast * lits, unsigned k)
void assert_at_most_k(Z3_context ctx, Z3_solver s, unsigned n, Z3_ast * lits, unsigned k)
{
Z3_ast * counter_bits;
unsigned counter_bits_sz;
if (k >= n || n <= 1)
return; /* nothing to be done */
counter_bits = mk_counter_circuit(ctx, n, lits, &counter_bits_sz);
assert_le_k(ctx, counter_bits_sz, counter_bits, k);
assert_le_k(ctx, s, counter_bits_sz, counter_bits, k);
del_bool_var_array(counter_bits);
}
@ -346,9 +346,9 @@ void assert_at_most_k(Z3_context ctx, unsigned n, Z3_ast * lits, unsigned k)
\brief Assert that at most one literal in \c lits can be true,
where \c n is the number of literals in lits.
*/
void assert_at_most_one(Z3_context ctx, unsigned n, Z3_ast * lits)
void assert_at_most_one(Z3_context ctx, Z3_solver s, unsigned n, Z3_ast * lits)
{
assert_at_most_k(ctx, n, lits, 1);
assert_at_most_k(ctx, s, n, lits, 1);
}
/**
@ -357,6 +357,7 @@ void assert_at_most_one(Z3_context ctx, unsigned n, Z3_ast * lits)
void tst_at_most_one()
{
Z3_context ctx = mk_context();
Z3_solver s = Z3_mk_solver(ctx);
Z3_ast k1 = mk_bool_var(ctx, "k1");
Z3_ast k2 = mk_bool_var(ctx, "k2");
Z3_ast k3 = mk_bool_var(ctx, "k3");
@ -368,29 +369,25 @@ void tst_at_most_one()
Z3_model m = 0;
Z3_lbool result;
printf("testing at-most-one constraint\n");
assert_at_most_one(ctx, 5, args1);
assert_at_most_one(ctx, 3, args2);
assert_at_most_one(ctx, s, 5, args1);
assert_at_most_one(ctx, s, 3, args2);
printf("it must be sat...\n");
result = Z3_check_and_get_model(ctx, &m);
result = Z3_solver_check(ctx, s);
if (result != Z3_L_TRUE)
error("BUG");
m = Z3_solver_get_model(ctx, s);
printf("model:\n%s\n", Z3_model_to_string(ctx, m));
if (m) {
Z3_del_model(ctx, m);
}
Z3_assert_cnstr(ctx, mk_binary_or(ctx, k2, k3));
Z3_assert_cnstr(ctx, mk_binary_or(ctx, k1, k6));
Z3_solver_assert(ctx, s, mk_binary_or(ctx, k2, k3));
Z3_solver_assert(ctx, s, mk_binary_or(ctx, k1, k6));
printf("it must be sat...\n");
result = Z3_check_and_get_model(ctx, &m);
result = Z3_solver_check(ctx, s);
if (result != Z3_L_TRUE)
error("BUG");
m = Z3_solver_get_model(ctx, s);
printf("model:\n%s\n", Z3_model_to_string(ctx, m));
if (m) {
Z3_del_model(ctx, m);
}
Z3_assert_cnstr(ctx, mk_binary_or(ctx, k4, k5));
Z3_solver_assert(ctx, s, mk_binary_or(ctx, k4, k5));
printf("it must be unsat...\n");
result = Z3_check_and_get_model(ctx, &m);
result = Z3_solver_check(ctx, s);
if (result != Z3_L_FALSE)
error("BUG");
Z3_del_context(ctx);
@ -407,7 +404,7 @@ unsigned get_num_disabled_soft_constraints(Z3_context ctx, Z3_model m, unsigned
Z3_ast t = Z3_mk_true(ctx);
for (i = 0; i < num_soft_cnstrs; i++) {
Z3_ast val;
if (Z3_eval(ctx, m, aux_vars[i], &val) == Z3_TRUE) {
if (Z3_model_eval(ctx, m, aux_vars[i], 1, &val) == Z3_TRUE) {
// printf("%s", Z3_ast_to_string(ctx, aux_vars[i]));
// printf(" -> %s\n", Z3_ast_to_string(ctx, val));
if (Z3_is_eq_ast(ctx, val, t)) {
@ -428,21 +425,21 @@ unsigned get_num_disabled_soft_constraints(Z3_context ctx, Z3_model m, unsigned
Exercise: use binary search to implement MaxSAT.
Hint: you will need to use an answer literal to retract the at-most-k constraint.
*/
int naive_maxsat(Z3_context ctx, unsigned num_hard_cnstrs, Z3_ast * hard_cnstrs, unsigned num_soft_cnstrs, Z3_ast * soft_cnstrs)
int naive_maxsat(Z3_context ctx, Z3_solver s, unsigned num_hard_cnstrs, Z3_ast * hard_cnstrs, unsigned num_soft_cnstrs, Z3_ast * soft_cnstrs)
{
Z3_ast * aux_vars;
Z3_lbool is_sat;
unsigned r, k;
assert_hard_constraints(ctx, num_hard_cnstrs, hard_cnstrs);
assert_hard_constraints(ctx, s, num_hard_cnstrs, hard_cnstrs);
printf("checking whether hard constraints are satisfiable...\n");
is_sat = Z3_check(ctx);
is_sat = Z3_solver_check(ctx, s);
if (is_sat == Z3_L_FALSE) {
// It is not possible to make the formula satisfiable even when ignoring all soft constraints.
return -1;
}
if (num_soft_cnstrs == 0)
return 0; // nothing to be done...
aux_vars = assert_soft_constraints(ctx, num_soft_cnstrs, soft_cnstrs);
aux_vars = assert_soft_constraints(ctx, s, num_soft_cnstrs, soft_cnstrs);
// Perform linear search.
r = 0;
k = num_soft_cnstrs - 1;
@ -451,19 +448,17 @@ int naive_maxsat(Z3_context ctx, unsigned num_hard_cnstrs, Z3_ast * hard_cnstrs,
unsigned num_disabled;
// at most k soft-constraints can be ignored.
printf("checking whether at-most %d soft-constraints can be ignored.\n", k);
assert_at_most_k(ctx, num_soft_cnstrs, aux_vars, k);
is_sat = Z3_check_and_get_model(ctx, &m);
assert_at_most_k(ctx, s, num_soft_cnstrs, aux_vars, k);
is_sat = Z3_solver_check(ctx, s);
if (is_sat == Z3_L_FALSE) {
printf("unsat\n");
return num_soft_cnstrs - k - 1;
}
m = Z3_solver_get_model(ctx, s);
num_disabled = get_num_disabled_soft_constraints(ctx, m, num_soft_cnstrs, aux_vars);
if (num_disabled > k) {
error("BUG");
}
if (m) {
Z3_del_model(ctx, m);
}
printf("sat\n");
k = num_disabled;
if (k == 0) {
@ -489,28 +484,27 @@ int naive_maxsat(Z3_context ctx, unsigned num_hard_cnstrs, Z3_ast * hard_cnstrs,
- replace aux-var with a new one
* add at-most-one constraint with blocking
*/
int fu_malik_maxsat_step(Z3_context ctx, unsigned num_soft_cnstrs, Z3_ast * soft_cnstrs, Z3_ast * aux_vars)
int fu_malik_maxsat_step(Z3_context ctx, Z3_solver s, unsigned num_soft_cnstrs, Z3_ast * soft_cnstrs, Z3_ast * aux_vars)
{
// create assumptions
Z3_ast * assumptions = (Z3_ast*) malloc(sizeof(Z3_ast) * num_soft_cnstrs);
Z3_ast * core = (Z3_ast*) malloc(sizeof(Z3_ast) * num_soft_cnstrs);
unsigned core_size;
Z3_ast dummy_proof; // we don't care about proofs in this example
Z3_model m;
Z3_lbool is_sat;
Z3_ast_vector core;
unsigned core_size;
unsigned i = 0;
for (i = 0; i < num_soft_cnstrs; i++) {
// Recall that we asserted (soft_cnstrs[i] \/ aux_vars[i])
// So using (NOT aux_vars[i]) as an assumption we are actually forcing the soft_cnstrs[i] to be considered.
assumptions[i] = Z3_mk_not(ctx, aux_vars[i]);
core[i] = 0;
}
is_sat = Z3_check_assumptions(ctx, num_soft_cnstrs, assumptions, &m, &dummy_proof, &core_size, core);
is_sat = Z3_solver_check_assumptions(ctx, s, num_soft_cnstrs, assumptions);
if (is_sat != Z3_L_FALSE) {
return 1; // done
}
else {
core = Z3_solver_get_unsat_core(ctx, s);
core_size = Z3_ast_vector_size(ctx, core);
Z3_ast * block_vars = (Z3_ast*) malloc(sizeof(Z3_ast) * core_size);
unsigned k = 0;
// update soft-constraints and aux_vars
@ -518,7 +512,7 @@ int fu_malik_maxsat_step(Z3_context ctx, unsigned num_soft_cnstrs, Z3_ast * soft
unsigned j;
// check whether assumption[i] is in the core or not
for (j = 0; j < core_size; j++) {
if (assumptions[i] == core[j])
if (assumptions[i] == Z3_ast_vector_get(ctx, core, j))
break;
}
if (j < core_size) {
@ -531,10 +525,10 @@ int fu_malik_maxsat_step(Z3_context ctx, unsigned num_soft_cnstrs, Z3_ast * soft
k++;
// Add new constraint containing the block variable.
// Note that we are using the new auxiliary variable to be able to use it as an assumption.
Z3_assert_cnstr(ctx, mk_binary_or(ctx, soft_cnstrs[i], new_aux_var));
Z3_solver_assert(ctx, s, mk_binary_or(ctx, soft_cnstrs[i], new_aux_var));
}
}
assert_at_most_one(ctx, k, block_vars);
assert_at_most_one(ctx, s, k, block_vars);
return 0; // not done.
}
}
@ -553,14 +547,14 @@ int fu_malik_maxsat_step(Z3_context ctx, unsigned num_soft_cnstrs, Z3_ast * soft
Z. Fu and S. Malik, On solving the partial MAX-SAT problem, in International
Conference on Theory and Applications of Satisfiability Testing, 2006.
*/
int fu_malik_maxsat(Z3_context ctx, unsigned num_hard_cnstrs, Z3_ast * hard_cnstrs, unsigned num_soft_cnstrs, Z3_ast * soft_cnstrs)
int fu_malik_maxsat(Z3_context ctx, Z3_solver s, unsigned num_hard_cnstrs, Z3_ast * hard_cnstrs, unsigned num_soft_cnstrs, Z3_ast * soft_cnstrs)
{
Z3_ast * aux_vars;
Z3_lbool is_sat;
unsigned k;
assert_hard_constraints(ctx, num_hard_cnstrs, hard_cnstrs);
assert_hard_constraints(ctx, s, num_hard_cnstrs, hard_cnstrs);
printf("checking whether hard constraints are satisfiable...\n");
is_sat = Z3_check(ctx);
is_sat = Z3_solver_check(ctx, s);
if (is_sat == Z3_L_FALSE) {
// It is not possible to make the formula satisfiable even when ignoring all soft constraints.
return -1;
@ -571,11 +565,11 @@ int fu_malik_maxsat(Z3_context ctx, unsigned num_hard_cnstrs, Z3_ast * hard_cnst
Fu&Malik algorithm is based on UNSAT-core extraction.
We accomplish that using auxiliary variables (aka answer literals).
*/
aux_vars = assert_soft_constraints(ctx, num_soft_cnstrs, soft_cnstrs);
aux_vars = assert_soft_constraints(ctx, s, num_soft_cnstrs, soft_cnstrs);
k = 0;
for (;;) {
printf("iteration %d\n", k);
if (fu_malik_maxsat_step(ctx, num_soft_cnstrs, soft_cnstrs, aux_vars)) {
if (fu_malik_maxsat_step(ctx, s, num_soft_cnstrs, soft_cnstrs, aux_vars)) {
return num_soft_cnstrs - k;
}
k++;
@ -596,19 +590,21 @@ int fu_malik_maxsat(Z3_context ctx, unsigned num_hard_cnstrs, Z3_ast * hard_cnst
int smtlib_maxsat(char * file_name, int approach)
{
Z3_context ctx;
Z3_solver s;
unsigned num_hard_cnstrs, num_soft_cnstrs;
Z3_ast * hard_cnstrs, * soft_cnstrs;
unsigned result = 0;
ctx = mk_context();
s = Z3_mk_solver(ctx);
Z3_parse_smtlib_file(ctx, file_name, 0, 0, 0, 0, 0, 0);
hard_cnstrs = get_hard_constraints(ctx, &num_hard_cnstrs);
soft_cnstrs = get_soft_constraints(ctx, &num_soft_cnstrs);
switch (approach) {
case NAIVE_MAXSAT:
result = naive_maxsat(ctx, num_hard_cnstrs, hard_cnstrs, num_soft_cnstrs, soft_cnstrs);
result = naive_maxsat(ctx, s, num_hard_cnstrs, hard_cnstrs, num_soft_cnstrs, soft_cnstrs);
break;
case FU_MALIK_MAXSAT:
result = fu_malik_maxsat(ctx, num_hard_cnstrs, hard_cnstrs, num_soft_cnstrs, soft_cnstrs);
result = fu_malik_maxsat(ctx, s, num_hard_cnstrs, hard_cnstrs, num_soft_cnstrs, soft_cnstrs);
break;
default:
/* Exercise: implement your own MaxSAT algorithm.*/