91.304 Foundations of Computer Science Review Topics Fall 15
Read the Preliminaries.pdf file.
You need to know everything from this notes especially from Pages 4-7. You should know
the concept of: set operations; DeMorgan laws; distributive laws; languag

The stack starts with a special symbol # at the bottom.
A string is accepted when the stack becomes completely empty when the string is
completely read (that means the input tape has a) — even the # symbol should be
popped.
Here is the logic to accept {a"

Example 1:
Prove that L = cfw_akbk | k 0 is not regular using pumping lemma
Proof:
Assume L is regular.
Since L is infinite and assumed to be regular pumping lemma holds for L.
According to the pumping lemma, there is a constant n that depends only on L a

Context-Free Languages and PushDown Automata
A generative grammar G is a quadruple G = (V, , S, P) where V is called the
non-terminal alphabet (or set of nonterminals); is called the terminal alphabet
(or set of terminals); S V is a distinguished start s

Chuong Vu
Sept 29, 2016
Foundation
HW0
0.1 a) A set of all odd natural numbers
b) A set of all even integer number
c) Even numbers
d) All positive number multiples of 6
e) Binary, palindromes numbers
f) Odd integer numbers
0.2 a) cfw_1, 10, 100
b) cfw_n Z