XBT_PUBLIC(lmm_system_t) lmm_system_new(int selective_update);
XBT_PUBLIC(void) lmm_system_free(lmm_system_t sys);
-void lmm_variable_disable(lmm_system_t sys, lmm_variable_t var);
XBT_PUBLIC(lmm_constraint_t) lmm_constraint_new(lmm_system_t sys, void *id,
double bound_value);