typedef struct lmm_element *lmm_element_t;
typedef struct lmm_variable *lmm_variable_t;
typedef struct lmm_constraint *lmm_constraint_t;
typedef struct lmm_element *lmm_element_t;
typedef struct lmm_variable *lmm_variable_t;
typedef struct lmm_constraint *lmm_constraint_t;