Question & Answer: Using JFLAP Given the alphabet of input symbols {a,b,c}. Use JFLAP to construct a PDA to recognize strings for which the…..

A = {Q, ∑, Γ, δ, q₀, z₀, F} where

Q = {q₀, q₁, q₂, q₃, q₄} = set of states

∑ = {a, b, c} = input alphabet

Γ = {a, b, c, z₀} = stack alphabet

F = {q₄}

The PDA should accept input strings with symbols a, b and c where number of a’s is twice that of c’s.

The transition function δ is

δ(q₀, c, z₀) = {(q₁, az₀)}

δ(q₁, c, c) = {(q₁, cc)}

δ(q₁, a, c) = {(q₂, c)}

δ(q₂, a, c) = {(q₃, λ)}

δ(q₃, a, c) = {(q₂, c)}

δ(q₂, b, c) = {(q₃, λ)}

δ(q₃, λ, z₀) = {(q₄, z0)}

Consider an input string aaaacc, the transitions are

δ(q₀, c, z₀) = {(q₁, cz₀)}

δ(q₁, c, c) = {(q₁, cc)}

δ(q₁, a, c) = {(q₂, c)}

δ(q₂, a, c) = {(q₃, λ)}

δ(q₃, a, c) = {(q₂, c)}

δ(q₂, a, c) = {(q₃, λ)}

δ(q₃, λ, z0) = {(q₄, z₀)}

Since it halts in final state, the string is accepted.