Andrew Pochinsky scripsit:

> If one takes a position that RnRS alone defines the language, then it  
> could only mean what it says, not the other way around.

In that case, see Section 7.2, Formal semantics:

# The order of evaluation within a call is unspecified. We mimic that
# here by applying arbitrary permutations permute and unpermute, which
# must be inverses, to the arguments in a call before and after they are
# evaluated. This is not quite right since it suggests, incorrectly,
# that the order of evaluation is constant throughout a program (for
# any given number of arguments), but it is a closer approximation to
# the intended semantics than a left-to-right evaluation would be.

So if it's incorrect to say that the order of evaluation is constant,
it is correct to say it is inconstant.

> It seems a rather unfortunate state that there are several places in
> RnRS that require a language lawyer well steeped in the history of
> functional programming to parse.

All standards are like this (as indeed are actual legal documents):
they must always be interpreted with regard to a community of practice.

-- 
It was impossible to inveigle           John Cowan <[email protected]>
Georg Wilhelm Friedrich Hegel           http://www.ccil.org/~cowan
Into offering the slightest apology
For his Phenomenology.                      --W. H. Auden, from "People" (1953)

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