ATC - MODULE 3-Part 2 V CSE 2017-18

Prepared By: Roopa G K , Asst. Prof, Dept of CSE, VCET Puttur Page 7

Exploiting non determinism:

ATC - MODULE 3-Part 2 V CSE 2017-18

Prepared By: Roopa G K , Asst. Prof, Dept of CSE, VCET Puttur Page 8

ATC - MODULE 3-Part 2 V CSE 2017-18

Prepared By: Roopa G K , Asst. Prof, Dept of CSE, VCET Puttur Page 9

Techniques for reducing non determinism:

a) Using a bottom of stack marker

• Need to detect bottom of stack, so push # onto the stack before we start.

b) Using an end-of string Marker

• Need to detect end of input. Add to L a termination character (e.g., $)

Non-determinism and halting:

ATC - MODULE 3-Part 2 V CSE 2017-18

Prepared By: Roopa G K , Asst. Prof, Dept of CSE, VCET Puttur Page 10

ATC - MODULE 3-Part 2 V CSE 2017-18

Prepared By: Roopa G K , Asst. Prof, Dept of CSE, VCET Puttur Page 11

Alternative equivalent Definition for PDA

i

ATC - MODULE 3-Part 2 V CSE 2017-18

Prepared By: Roopa G K , Asst. Prof, Dept of CSE, VCET Puttur Page 12