Chapter 19
LL(k) Grammars
LL(k) Parsers
s
s
Can be developed using PDAs for parsing CFGs by
converting the machines directly into program
statements
Describe the parsing strategy:
i) the input string is scanned in a left-to-right manner
ii) the parsers ge

Chapter 15
P, NP, and Cooks
Theorem
Computability Theory
s
s
Establishes whether decision problems are theoretically
decidable, i.e., decides whether each solvable problem has a
practical solution that can be solved efficiently
A theoretically solvable pr

Chapter 14
Time Complexity
Time Complexity
s
s
s
The study of complexity of a problem is the study of
the complexity of the algorithm that solves the
problem.
The computational complexity of an algorithm is
measured by the amount of resources required
car

Chapters 11 and 12
Decision Problems and
Undecidability
11.1 Decision Problems
s
A decision problem
s
consists of a set of questions whose answers are either
yes or no
is undecidable if no algorithm that can solve the problem;
otherwise, it is decidable
T

Chapter 8
Turing Machine (TMs)
Turing Machines
s
s
s
s
Accepts the languages that can be generated by unrestricted
(phrase-structured) grammars
No computational machine (i.e., computational language
recognition system) is more powerful than the class of
T

Chapter 7
PDA and CFLs
7.1 PDA
s
s
s
Is an enhanced FSAs with an internal memory system,
i.e., a (pushdown) stack.
Overcomes the memory limitations and increases the
processing power of FSAs.
Defn. 7.1.1 A pushdown automaton (PDA) is a
sextuple (Q, , , ,

Chapter 6
Properties of
Regular Languages
Regular Sets and Languages
Claim(1). The family of languages accepted by FSAs consists
of precisely the regular sets over a given alphabet.
Every regular set is accepted by some NFA-,
a) :
q0
b) :
q0
c) a :
q0
q

Chapter 5
Finite Automata
5.1 Finite State Automata
s
s
s
Capable of recognizing numerous symbol patterns,
the class of regular languages
Suitable for pattern-recognition type applications,
such as the lexical analyzer of a compiler
An abstract (computing

Chapter 4
Normal Forms
for CFGs
4.5 Chomsky Normal Form
s
Defn 4.4.1 A CFG G = (V, , P, S) is in chomsky normal
form if each rule in G has one of the following forms:
i) A BC
ii) A a
iii) S
where A, B, C V and B, C V - cfw_S and a
s
s
A simplified norma

Chapter 3
Context-Free
Grammars
Context-Free Grammars and Languages
s
Defn. 3.1.1 A context-free grammar is a quadruple (V, ,
P, S), where
s
V is a finite set of variables (non-terminals)
, the alphabet, is a finite set of terminal symbols
P is a finite s

Chapter 2
Languages
Languages
s
Defn. A language is a set of strings over an alphabet.
s
A more restricted definition requires some forms of
restrictions on the strings, i.e., strings that satisfy
certain properties
Defn. The syntax of a language restrict