Given homomorphism h : and language L dene h(L)={h(w)|wL} How to write formal proof for: all strings x,y, h(xy)=h(x)h(y) 2. h(L1L2)=h(L1)h(L2) 3.

Given homomorphism h : Σ∗→∆∗ and language L⊆Σ∗ define h(L)={h(w)|w∈L}⊆∆∗

How to write formal proof for:

1. all strings x,y∈Σ∗, h(xy)=h(x)h(y)

2. h(L1∪L2)=h(L1)∪h(L2)

3. h(L1◦L2)=h(L1)◦h(L2)