int lmm_get_number_of_cnst_from_var(lmm_system_t sys, lmm_variable_t var);
lmm_variable_t lmm_get_var_from_cnst(lmm_system_t sys,
lmm_constraint_t cnst,
int lmm_get_number_of_cnst_from_var(lmm_system_t sys, lmm_variable_t var);
lmm_variable_t lmm_get_var_from_cnst(lmm_system_t sys,
lmm_constraint_t cnst,