lmm_constraint_t cnst,
lmm_variable_t * var);
+lmm_constraint_t lmm_get_first_active_constraint(lmm_system_t sys);
+lmm_constraint_t lmm_get_next_active_constraint(lmm_system_t sys, lmm_constraint_t cnst);
+
void *lmm_constraint_id(lmm_constraint_t cnst);
void *lmm_variable_id(lmm_variable_t var);