[plt-scheme] Error...

> However, I forgot (error ...) was not in R5RS and I
> was thinking about providing them a way to notice users of errors when
> they happen.

This is exactly what we mean when we say R5RS is not a programming
language.  Programming languages are sensitive to the fact that programs
may contain errors.  Specification languages, in contrast, assume that they
are describing a ground truth.  R5RS is a specification language for algorithms.

Please don't put your students through the misery of programming in R5RS.
What point are you trying to make?  How are you doing anything but giving
the impression that Scheme is a brain-dead language that lacks even the most
basic capabilities of other languages they have seen?

Shriram