fixup! grammar

Author: ulysses4ever

markdown/source_md/types-and-typeclasses.md

@@ -199,7 +199,7 @@ ghci> :t (==)
 ::: {.hintbox}
 **Note**: the equality operator, `==` is a function.
 So are `+`, `*`, `-`, `/` and pretty much all operators.
-If a function name comprised only special characters, it's considered an infix function by default.
+If a function name is comprised only of special characters, it's considered an infix function by default.
 If we want to examine its type, pass it to another function or call it as a prefix function, we have to surround it in parentheses.
 :::