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Wired numeric predicates?
I understand your rationale for not wanting numeric predicates to be special
forms. The reason I brought it up was that I am a Teaching Assistant in an
undergrad course this term that uses Scheme. A student raised the issue since
it seems natural to think of (< x1 x2 x3...) as being the AND of each of the
individual two-step comparisons. The resemblence between this and the AND
form were sufficiently strong that the student conveniently ignored the fact
that we explicitly describe < as being a *procedure* and not as a *special
form*... I guess people naturally don't look carefully at things that they
consider ``intuitively obvious''. (Actually, MIT Scheme also defines AND to be
a procedure, but we had blown this at the time... the student wanted to know
6.001 Scheme has AND as a procedure because SICP used it that way.
AND is a special form in MIT Scheme, of which 6.001 is not a subset.
I haven't thought about it carefully, but it may not be reasonable
(unless it is defined that way) to implement n-ary < and friends as
the "AND accumulation" of binary <. Comparisons between exact and
inexact numbers should coerce the exact numbers to inexact, and this
value may have to be used consistently afterwards.