void lmm_variable_free(lmm_system_t sys, lmm_variable_t var);
XBT_PUBLIC(double) lmm_variable_getvalue(lmm_variable_t var);
XBT_PUBLIC(double) lmm_variable_getbound(lmm_variable_t var);
-XBT_PUBLIC(double) lmm_variable_getdf(lmm_variable_t var);
XBT_PUBLIC(void) lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
lmm_variable_t var, double value);