--- a/hws/hw01.tex Mon Sep 22 01:57:59 2014 +0100
+++ b/hws/hw01.tex Mon Sep 22 02:01:41 2014 +0100
@@ -48,15 +48,15 @@
\item How many regular expressions are there to match the
string $abc$? (How many if they cannot include
- $\epsilon$ and $\varnothing$? How many if they also are
- not allowed to contain stars? How many if they also are
+ $\epsilon$ and $\varnothing$? How many if they are also
+ not allowed to contain stars? How many if they are also
not allowed to contain $\_ + \_$?)
\item When are two regular expressions equivalent? Can you
- think of instances where two regular expressions are
- equivalent, but it is not so obvious that they are? For
+ think of instances where two regular expressions match
+ teh same strings, but it is not so obvious that they do? For
example $a + b$ and $b + a$ do not count\ldots they
- are obviously equivalent.
+ obviously match the same strings, namely $[a]$ and $[b]$.
\end{enumerate}