Final lambda edits

Advanced/Lambda Calculus/parts/05 challenges.tex

@@ -39,7 +39,8 @@ Design a non-recursive factorial function. \par
 
 
 \problem{}
-Solve \ref{decrement} without using $H$.
+Solve \ref{decrement} without using $H$. \par
+In \ref{decrement}, we created the \say{decrement} function.
 
 \begin{solution}
 	One solution is below. Can you figure out how it works? \par
@@ -118,7 +119,7 @@ Write a lambda expression that evaluates to $T$ if a number $n$ is prime, and to
 \vfill
 
 \problem{}
-Write a MOD $a$ $b$ function that reduces to the remainder of $a \div b$.
+Write a function MOD so that $(\text{MOD}~a~b)$ reduces to the remainder of $a \div b$.
 
 \vfill