Consider the Deterministic Finite Automata,
A = (QA, ΣA, δA, q0A, FA) and B = (QB, ΣB, δB, q0B, FB) with
QA ∩ QB = ∅, ΣA ∩ ΣB = ∅ where ∅ stands for the null set.
Let LA ⊆ ΣA* and LB ⊆ ΣB* be the languages accepted by A and B respectively and define the interleaved language:
LA || LB := {s ∈ (ΣA ∪ ΣB)* | s ↑ A ∈ LA and s ↑ B ∈ LB}
where s ↑ A and s ↑ B stand for the projection of s on ΣA and ΣB obtained by erasing all the symbols of s in ΣB and ΣA respectively.
(a) Define the interleaving product A || B of A and B as a DFA that accepts the language LA || LB
(b) Compute a DFA that accepts the language L = (0.1)* || (a.b)*