hws/hw02.tex
changeset 132 04264d0c43bb
parent 115 86c1c049eb3e
child 258 1e4da6d2490c
--- a/hws/hw02.tex	Mon Oct 07 09:34:12 2013 +0100
+++ b/hws/hw02.tex	Mon Oct 07 09:45:11 2013 +0100
@@ -14,7 +14,9 @@
 in general for arbitrary languages $A$, $B$ and $C$:
 \begin{eqnarray}
 (A \cup B) @ C & = & A @ C \cup B @ C\nonumber\\
-A^* \cup B^* & = & (A \cup B)^*\nonumber\\
A^* @ A^*  & = & A^*\nonumber\\
(A \cap B)@ C & = & (A@C) \cap (B@C)\nonumber
+A^* \cup B^* & = & (A \cup B)^*\nonumber\\
+A^* @ A^*  & = & A^*\nonumber\\
+(A \cap B)@ C & = & (A@C) \cap (B@C)\nonumber
 \end{eqnarray}
 
 \noindent
@@ -36,8 +38,6 @@
 \item Given the regular expression $r = (a \cdot b + b)^*$. Compute what the derivative of $r$ is with respect to
 $a$ and $b$. Is $r$ nullable?
 
-\item What is a regular language?
-
 \item Prove that for all regular expressions $r$ we have
 \begin{center}
 $\text{nullable}(r)$ \quad if and only if \quad $\texttt{""} \in L(r)$