Answer
Let G1 and G2 be context-free grammars, generating
the languages L(G1) and L(G2), respectively. Showing
that there is a context-free grammar generating each of
these sets.
a) L(G1) ∪ L(G2)
b) L(G1)L(G2)
c) L(G1)*
Work Step by Step
Let S1 and S2 be the start symbols
of G1 and G2, respectively. Let S be a new start symbol.
a) Add S and productions S → S1 and S → S2.
b) Add S and production S → S1 S2.
c) Add S and production S → λ and S → S1S.
