e/Reduction of the structure group

Information
has gloss	eng: Formally, given a G-bundle B and a map H → G (which need not be an inclusion), a reduction of the structure group (from G to H) is an H-bundle B_H such that the pushout B_H \times_H G is isomorphic to B.
lexicalization	eng: reduction of the structure group
instance of	c/Structures on manifolds

Meaning
Chinese
has gloss	zho: 数学中，特别是在主丛理论中，我们可问一个 G-丛能否“来自”一个子群 H < G。这称为结构群的约化（，约化为 H），且对任何映射 H\to G 有意义，不必要求是包含（尽管使用了这个术语）。
lexicalization	zho: 结构群的约化