Lecture 3

Proving a Language is Regular
Method 5
Use closure properties
Example L = {w∊(0+1)* | w is a binary
number divisible by 5 consisting of a bunch of
0s squeezed between two bunches of 1s}
We know
1) {binary numbers divisible by 5} is regular
2) bunch of 0s squeezed between 1s is 1 * 0 * 1 *
hence regular
Cite closure under intersection and we’re done!
Friday, February 8, 13