R6RS provides support for inexact infinities and NaN objects. Do we keep these, and if so do we use the same literal syntax and arithmetic as in R6RS?
Larceny certainly handles the +info.0 syntax. I am in favor of having explicit representations for infinities and NaN in any case...
The WG voted to accept this feature just as in R6RS.
Testing Schemes with +inf.0 -inf.0 +nan.0, and if required (/ 1.0, 0.0) (/ 0.0 0.0):
PLT, Gauche, Gambit, Chicken[1], Bigloo, Guile, Chez, Chibi understand the syntaxes.
MIT, Scheme48/scsh, Kawa[2], SISC[3], SCM[4], Scheme 9, Scheme 7, VSCM do not.
SSCM doesn't seem to support anything but small exact integers.
[1] Chicken accepts the standard syntax, but outputs +inf, -inf, +nan without the .0 [2] Kawa uses the syntax #i1/0, #i-1/0, #i0/0 [3] SISC outputs infinity.0, -infinity.0, nan.0 but does not accept them on input [4] SCM accepts and outputs +inf.0 and -inf.0, but uses 0/0 for NaNs.
I recommend that we accept the R6RS syntax.