ECS 120 Homework 4 Due April 26
1. Linz, Section 3.2: 4c, 9, 15
Section 3.3: 6,10, 14
2. Define a string operation that removes the rightmost symbol from a string, that
is, , for all and
chop
wwachop =)( *Σ∈w
Σ
∈
a. We can extend this operation to languages
by
}somefor :*{)(
Σ
∈
∈Σ∈= aLvavLchop .
Let M be the finite automaton in file JHW4 and let )(MLL
=
. Modify M to produce a
new finite automaton , so that
1
M
.
)()( 1LchopML =
3. Generalize the construction you used to solve Part 2, and prove that it always works.
Then use this to show that the family of regular languages is closed under the chop
operation.
Note: Please turn in JFLAP files for Problem 1: 4c and Problem 2.
Use the handin utility on CSIF for electronic submission:
For example, if you’re submitting the file “problem1_4c.jff”s, use the following
command on your CSIF account:
> handin shini hw4 problem1_4c.jff
