diff -r 293ea84d82ca -r 62389faa66e4 cws/cw04.tex
--- a/cws/cw04.tex	Fri Jan 27 14:55:56 2017 +0000
+++ b/cws/cw04.tex	Wed Feb 01 13:54:55 2017 +0000
@@ -13,13 +13,13 @@
 
 \noindent
 \textbf{Important:} Do not use any mutable data structures in your
-submission! They are not needed. This excludes the use of
+submission! They are not needed. This menas you cannot use 
 \texttt{ListBuffer}s, for example. Do not use \texttt{return} in your
 code! It has a different meaning in Scala, than in Java.  Do not use
 \texttt{var}! This declares a mutable variable.  Make sure the
 functions you submit are defined on the ``top-level'' of Scala, not
 inside a class or object. Also note that the running time will be
-restricted to a maximum of 360 seconds.
+restricted to a maximum of 360 seconds on my laptop.
 
 
 \subsection*{Disclaimer}
@@ -43,7 +43,7 @@
 \item[(1)] First write a polymorphic function that recursively
   transforms a list of options into an option of a list. For example,
   if you have the lists on the left-hand side, they should be transformed into
-  the option on the right-hand side:
+  the options on the right-hand side:
 
   \begin{center}
   \begin{tabular}{lcl}