build stmt mpz_init(v) or mpq_init(v) depending on typ of v

init_set x_as_lv x_as_exp e builds stmt x = e or mpz_init_set*(v, e) or mpq_init_set*(v, e) with the good function 'set' according to the type of e

build stmt mpz_clear(v) or mpq_clear(v) depending on typ of v

assign x_as_lv x_as_exp e builds stmt x = e or mpz_set*(e) or mpq_set*(e) with the good function 'set' according to the type of e