10 Reducibility
10.1 What is reducibility?
Reading: Sipser 5 (pp. 187-188)
We say that problem A reduces (or is reducible) to problem B, if we can use a solution to B to solve A (i.e., if B is
decidable/solvable, so is A.).
We may use reducibility to prov
3 Regular expressions
3.1 Denition
Reading: Sipser 1.3 (pp. 63-66)
In addition to DFAs and NFAs, regular expressions (REs) also represent regular languages. Let L(R) be the language
that regular expression R represents. A recursive denition for R (and L(R
Error Handling
Syntax-Directed Translation
Recursive Descent Parsing
Lecture 6
Prof. Aiken CS 143 Lecture 6
1
Announcements
PA1
Due today at midnight
README, test case
Your name(s)!
WA1
Due today at 5pm
PA2
Assigned today
WA2
Assigned today
Prof
Probability Models and Statistical
Methods in Reliability
Larry Leemis
Department of Mathematics
College of William and Mary
Williamsburg, VA 23187-8795
[email protected] 757-221-2034
Undergraduate Simulation, Modeling and Analysis
February 14, 2000
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Applications of Congruences and
Cryptography
Rosen 4.5, 4.6
CS 243 Discrete Mathematics
sources: K. Rosen, I. Dillig
1
Congruences
many practical applications of congruences
assign memory locations to computer files
generate pseudorandom numbers
compu
Propositional Logic III
Rosen 1.4, 1.5
CS 243 Discrete Mathematics
sources: K. Rosen, I. Dillig
1
Predicate Logic
so far, we have reviewed the simplest logic, propositional logic
we can use propositional logic for making valid inferences and
arguments
Propositional Logic II
Rosen 1.2, 1.3
CS 243 Discrete Mathematics
sources: K. Rosen, I. Dillig
1
Applications of Propositional Logic
logic is used in many different disciplines, including
mathematics
computer science
natural sciences
criminology
apo
Propositional Logic I
Rosen 1.1
CS 243 Discrete Mathematics
sources: K. Rosen, I. Dillig
1
English Statements for Implication
All of the following are expressions of p q:
if p then q
if p, q
p is sufficient for q
q if p
q when p
a necessary condition for