Regular Language and
Regular Grammar
Objectives
•Regular Expression and Regular
Language
•Regular Expression vs Regular Language
•Regular Grammar
Regular Expression
Alphabet Σ
1. ∅, λ, a∈Σ are regular expressions
(known as primitive regular
expressions).
2. If r1 and r2 are regular expressions,
so are r1 + r2, r1 . r2, r1*, and (r1).
Operator Precedence
•parentheses
•star-closure (*)
•concatenation (.)
•union (+)
Languages Associated with Regular
Expressions
•Each regular expression stands for a set
of strings of symbols in Σ each regular
expression represents a language, called
regular language
•r L(r)