例句與造句

1. According to Schreier's subgroup lemma, a set of generators for a free presentation of may be constructed from cycles in the covering graph formed by concatenating a spanning tree path from a base point ( the coset of the identity ) to one of the cosets, a single non-tree edge, and an inverse spanning tree path from the other endpoint of the edge back to the base point.
2. It's difficult to find presentation of may in a sentence. 用presentation of may造句挺難的