SYCS 341
Theory of Computation
Instructor: Dr. Chunmei Liu
Office: LKD 2038
Office phone: 202-865-0056, email:
chunmei@scs.howard.edu
Meeting time: TR 12:10pm-1:30pm
What is this course about?
It is about models of computation, their
power, and relations

Chapter 1: Regular Languages
1
Finite Automata
One pass through the input
No capability to write
Turing Machines with constant amount of
memory
2
Finite Automata
5-tuple descriptions
State diagrams
DFAs
NFAs
Regular expressions
Any language compu

NFA with epsilon transitions
Sipser pages 47-54
NFAs with Transitions
We extend the class of NFAs by allowing
instantaneous () transitions:
1. The automaton may be allowed to change its
state without reading the input symbol.
2. In diagrams, such transit

Chapter 2: Context-Free Languages
1
Cardinality
Def: A set is countable if it is
(i) finite or
(ii) countably infinite.
Def: A set S is countable infinite if there is a
bijection from N to S.
Note: Instead of N to S we can also say S to N.
N = cfw_0, 1