Lecture 8 - Intro Flashcards
1
Q
What can a DFA not recognise?
A
a^nb^n
- specific numbers of letters
2
Q
Why cannot DFA recognise this?
A
As there are infinitely many values for n , so this means there could be an infinite amount of states
-> this is a FINITE machine
3
Q
How to recognise a^nb^n?
A
We need some sort of memory
- e.g. a stack
4
Q
Is DFA an adequate model of the computer i.e. black box
A
no
5
Q
How can we solve the a^nb^n problem?
A
With a pushdown automata.
