Question

Generate a PDA for the following constrained regular expression: (a+b)+(c+d)+a under the constraint that the number of ' c ' characters is equal to the number of 'a' characters. Submit a JFlap file only.

Answer 1

To generate a PDA for the constrained regular expression (a+b)+(c+d)+a under the constraint that the number of 'c' characters is equal to the number of 'a' characters, you can use JFlap software.

Step-by-step explanation:

To generate a PDA for the constrained regular expression (a+b)+(c+d)+a under the constraint that the number of 'c' characters is equal to the number of 'a' characters, you can use JFlap software. Here are the steps to create the PDA:

1. Create three states: q0, q1, and q2.
2. Set q0 as the initial state and q2 as the final state.
3. For every 'a' or 'b' character, transition from q0 to q1. For every 'c' or 'd' character, transition from q1 to q2.
4. To ensure the constraint of the number of 'c' characters being equal to the number of 'a' characters, you can use a stack. Whenever a 'c' character is read, push a symbol onto the stack. Whenever an 'a' character is read, pop a symbol from the stack. If the stack is empty at the end, the constraint is satisfied.

You can download and import the JFlap file for this PDA here.