Alex Shinn scripsit:

> [...] Otherwise #4, fork maximally, renaming in favor of
> consistency with SRFI 1 and R7RS.

I think by #4 you mean #3.

(All that said, the inability, given a Scheme procedure, to determine
*anything* about its calling protocol is a definite weakness/restriction in
Scheme that ought to be removed, though I have no idea how at the moment.
Arity inspection solves part of the problem, but wouldn't be sufficient here.