The properties kept by homomorphism of rings are generalized by restricting zero divisors of rings, and some important theorems are proved.
通过对环的零因子进行限制，推广了环同态所保持的性质，证明了几个重要的定理。
After the homomorphic mapping of two linear spaces is defined, the influence on zero, negative element and subspace of linear space is discussed, and then the fundmental theorem of homomorphism is also given.