03-08-2012, 04:29 PM
Theory of Computation
1Theory of Computation.ppt (Size: 259 KB / Downloads: 44)
IMPORTANT NOTES
Students…
This presentation is designed to be used in class as part of a guided discovery sequence. It is not self-explanatory! Please use it only for revision purposes after having taken the class. Simply going through the slides will teach you nothing. You must be actively thinking, doing and questioning to learn!
Course Strategy
Be Warned: This is not a course that spoon-feeds students.
Students are expected to be investigative and resourceful.
Reading books and other research of topics are expected.
Regular Expression
Definition
A regular expression, or RE, describes strings of characters (words or phrases or any arbitrary text). It's a pattern that matches certain strings and doesn't match others. A regular expression is a set of characters that specify a pattern.
OR Language defining symbols.
Regular expressions are used to generate patterns of strings. A regular expression is an algebraic formula whose value is a pattern consisting of a set of strings, called the language of the expression.
Operands in a regular expression
Operands in a regular expression can be:
characters from the alphabet over which the regular expression is defined.
variables whose values are any pattern defined by a regular expression.
epsilon which denotes the empty string containing no characters.
null which denotes the empty set of strings.
1Theory of Computation.ppt (Size: 259 KB / Downloads: 44)
IMPORTANT NOTES
Students…
This presentation is designed to be used in class as part of a guided discovery sequence. It is not self-explanatory! Please use it only for revision purposes after having taken the class. Simply going through the slides will teach you nothing. You must be actively thinking, doing and questioning to learn!
Course Strategy
Be Warned: This is not a course that spoon-feeds students.
Students are expected to be investigative and resourceful.
Reading books and other research of topics are expected.
Regular Expression
Definition
A regular expression, or RE, describes strings of characters (words or phrases or any arbitrary text). It's a pattern that matches certain strings and doesn't match others. A regular expression is a set of characters that specify a pattern.
OR Language defining symbols.
Regular expressions are used to generate patterns of strings. A regular expression is an algebraic formula whose value is a pattern consisting of a set of strings, called the language of the expression.
Operands in a regular expression
Operands in a regular expression can be:
characters from the alphabet over which the regular expression is defined.
variables whose values are any pattern defined by a regular expression.
epsilon which denotes the empty string containing no characters.
null which denotes the empty set of strings.