/*
* Check satisfiability and get a model
* - ctx = the context
* - parameters = heuristic settings (if parameters is NULL, the defaults are used)
* - var = array of n uninterpreted terms
* - n = size of array evar and value
* Output parameters;
* - value = array of n terms (to receive the value of each var)
* - model = to export the model (if model is NULL, nothing is exported)
*
* The return code is as in check_context:
* 1) if code = STATUS_SAT then the context is satisfiable
* and a model is stored in value[0 ... n-1]
* - value[i] = a constant term mapped to evar[i] in the model
* 2) code = STATUS_UNSAT: not satisfiable
*
* 3) other codes report an error of some kind or STATUS_INTTERRUPT
*/
static smt_status_t satisfy_context(context_t *ctx, const param_t *parameters, term_t *var, uint32_t n, term_t *value, model_t **model) {
smt_status_t stat;
model_t *mdl;
int32_t code;
assert(context_status(ctx) == STATUS_IDLE);
stat = check_context(ctx, parameters);
switch (stat) {
case STATUS_SAT:
case STATUS_UNKNOWN:
mdl = yices_get_model(ctx, true);
code = yices_term_array_value(mdl, n, var, value);
if (model != NULL) {
*model = mdl;
} else {
yices_free_model(mdl);
}
if (code < 0) {
// can't convert the model to constant terms
stat = STATUS_ERROR;
}
break;
default:
// can't build a model
break;
}
return stat;
}
int example2_main(void) {
type_t real;
term_t t, a;
int32_t code;
context_t *ctx;
model_t *mdl;
/*
* Global initialization: this must called first.
*/
yices_init();
/*
* Create an uninterpreted term of type real and call it "x"
*/
real = yices_real_type();
t = yices_new_uninterpreted_term(real);
code = yices_set_term_name(t, "x");
/*
* If code is negative, something went wrong
*/
if (code < 0) {
printf("Error in yices_set_term\n");
yices_print_error(stdout);
fflush(stdout);
goto done;
}
/*
* Create the atom (x > 0)
*/
a = yices_arith_gt0_atom(t);
/*
* Print the atom:
*/
printf("Atom: ");
yices_pp_term(stdout, a, 120, 2, 6);
/*
* Check that (x > 0) is satisfiable and get a model
* - create a context
* - assert atom 'a' in this context
* - check that the context is satisfiable
*/
ctx = yices_new_context(NULL); // NULL means use the default configuration
code = yices_assert_formula(ctx, a);
if (code < 0) {
printf("Assert failed: ");
yices_print_error(stdout);
fflush(stdout);
goto done;
}
switch (yices_check_context(ctx, NULL)) { // NULL means default heuristics
case STATUS_SAT:
// build the model and print it
printf("Satisfiable\n");
mdl = yices_get_model(ctx, true);
code = yices_pp_model(stdout, mdl, 120, 100, 0);
if (code < 0) {
printf("Print model failed: ");
yices_print_error(stdout);
fflush(stdout);
goto done;
}
// cleanup: delete the model
yices_free_model(mdl);
break;
case STATUS_UNSAT:
printf("Unsatisfiable\n");
break;
case STATUS_UNKNOWN:
printf("Status is unknown\n");
break;
case STATUS_IDLE:
case STATUS_SEARCHING:
case STATUS_INTERRUPTED:
case STATUS_ERROR:
// these codes should not be returned
printf("Bug: unexpected status returned\n");
break;
}
/*
* Delete the context: this is optional since yices_exit
* would do it anyway.
*/
yices_free_context(ctx);
done:
/*
* Global cleanup: free all memory used by Yices
*/
yices_exit();
return 0;
}
