-These functions are all objects of class @code{function}. They accept one
-or more expressions as arguments and return one expression. If the arguments
-are not numerical, the evaluation of the function may be halted, as it
-does in the next example:
+These functions are all objects of class @code{function}. They accept
+one or more expressions as arguments and return one expression. If the
+arguments are not numerical, the evaluation of the function may be
+halted, as it does in the next example, showing how a function returns
+itself twice and finally an expression that may be really useful: