Uniqueness of permutable entire functions;

In this Paper, the author proved the theorem: Let f(z)be an nonconstant periodic function of exponential type and positive lower order, and g(z) be an entire function of finite order If g(z) is permutable with f(z), then g(z)≡f(z)or g(z)≡

For a finite commutative Thue system(Σ∶R),let Δ R=｛((t 1,t 2,…,t n),(s 1,s 2,…,s n))｜(a t 1 1a t 2 2…a t n n→a s 1a s 2 2…a s n n)∈R｝.

To a finite commutative,special Thue system (Σ:R),(Σ:R)is a finite generated、commutative group.

In this paper,we mainly discuss on the commutativity of orthogonal projections on a complex separable Hilbert space.

Additive surjective map of strong preserve the set of rank permutability on triangular matrix spaces;

This paper gets a weakly exchangeable law of quaternion product by means of quaternion to be expressed vector.