例句與造句

1. As with all universal constructions, a coequalizer, if it exists, is unique up to a unique isomorphism ( this is why, by abuse of language, one sometimes speaks of " the " coequalizer of two parallel arrows ).
2. However, not every diagram commutes ( the notion of diagram strictly generalizes commutative diagram ) : most simply, the diagram of a single object with an endomorphism ( f \ colon X \ to X ), or with two parallel arrows ( \ bullet \ rightrightarrows \ bullet, that is, f, g \ colon X \ to Y, sometimes called the free quiver ), as used in the definition of equalizer need not commute.
3. It's difficult to find parallel arrow in a sentence. 用parallel arrow造句挺難的