{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

midterm_probs

# midterm_probs - CS 452 Formal Languages and Automata Theory...

This preview shows pages 1–2. Sign up to view the full content.

CS 452 Formal Languages and Automata Theory Summer 2004 Midterm Problems Problem 1. (22 pts) Consider the regular expression α = ( a ab b ) . (a) (2 pts) Find strings u and v of length | u | = | v | = 7, such that u L ( α ) and v / L ( α ). (b) •• (10 pts) Construct a DFA that accepts the language L ( α ) that is charac- terized by the regular expression α . (c) •• (10 pts) Given some regular expression R , can you think of a method to come up with a regular expression R , such that L ( R ) = L ( R ) ? Use that method to build a regular expression α that characterizes the lan- guage L ( α ) = L ( α ) for the regular expression given above. Problem 2. (35 pts) For each of the following languages decide whether it is a regular or a context free language or neither. If it is regular or context free show it by providing either a regular expression, a finite automaton ( DFA or NFA , your choice), a PDA , or a context free grammar that characterizes the language. Use each representation at least once.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 2

midterm_probs - CS 452 Formal Languages and Automata Theory...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online