Regular Languages

• A language is regular if its syntax can be expressed by a single EBNF rule without recursion.
• Since there is only one, non-recursive rule all symbols on the right-hand side must be terminal symbols. The right-hand side is also called a regular expression .
• Regular languages are interesting because they can be recognized by finite state machines .
• Alternatively, a language is regular if its syntax can be described by a number of EBNF rules without recursion.

Example: