- using a \hs{case} construct and the other using a \hs{if-then-else}
- constructs, in the code below.
+ using a \hs{case} construct and the other using an \hs{if-then-else}
+ construct, in the code below. The examples sums two values when they are
+ equal or non-equal (depending on the given predicate, the \hs{pred}
+ variable) and returns 0 otherwise. The \hs{pred} variable has the
+ following, user-defined, enumeration datatype: