int isl_seq_first_non_zero(isl_int *p, unsigned len);
int isl_seq_abs_min_non_zero(isl_int *p, unsigned len);
int isl_seq_eq(isl_int *p1, isl_int *p2, unsigned len);
+int isl_seq_is_neg(isl_int *p1, isl_int *p2, unsigned len);
u_int32_t isl_seq_hash(isl_int *p, unsigned len, unsigned bits);