Re: [stack] sweetening concatenative syntax

> > In other words you can't write code (in R5RS) that distinguishes
> > whether a given value is a closure, a function or a procedure.
>
> Closures satisfy PROCEDURE?, procedures satisfy PAIR? (and more specific
> predicates). Functions are abstracta, and don't have representations
> in Scheme.

That is interesting. I can't find in the specification
(http://schemers.org/Documents/Standards/R5RS/r5rs.pdf) that closures
must not satisfy "PAIR?". Can you point it out?

- Christopher