Question

Give an informal description of a pushdown automaton that recognizes the language in Exercise 2.9.

Short answer

Informal description of the pushdown automaton that recognizes the language can be given.

$A=\{a^j{b}^j{c}^k|i=jorj=kwherei,j,k\ge 0\}canbegiven$

Step-by-step solution

Explain pushdown automaton

Pushdown Automaton write symbols on the stack and read them. Writing a new symbol pushes down all the symbols in the stack before.

Give an informal description of a pushdown automaton that recognizes the language A.

Informal description of the pushdown automaton that recognizes the language

$A=\{a^j{b}^j{c}^k|i=jorj=kwherei,k\ge 0\}isasfollows$

1. Nondeterministic, branching to step 2 or 6.
2. Read and push a ’s.
3. Pop a’s, and read b ’s.
4. If stack is empty,accept.
5. Skip a’s and c’s input.
6. Push b’s
7. Read c ’s.
8. When stack is empty and c’s finish, accept.

Therefore, the informal description has been given