value_clone (&vn->val, &nst->val1, var_get_width (nst->indep_var));
hmap_insert (&map, &vn->node, value_hash (&nst->val1,
var_get_width (nst->indep_var), 0));
value_clone (&vn->val, &nst->val1, var_get_width (nst->indep_var));
hmap_insert (&map, &vn->node, value_hash (&nst->val1,
var_get_width (nst->indep_var), 0));