descriptionR5RS and draft 6 of R7RS don't say what `(log 0.0)` and `(log 0)` return. R6RS requires `-inf.0` and an exception respectively. The proposal is to say that `(log 0.0)` returns `-inf.0` on systems that have `+inf.0`, and that `(log 0)` is an error.
In Racket, Gambit, Chicken (with the numbers egg), Guile, Chibi, Chez, !Ikarus/Vicare, Larceny, Ypsilon, Mosh, !IronScheme, STklos, Spark, `(log 0.0)` returns `-inf.0` and `(log 0)` raises an exception.
Gauche, Chicken (without the numbers egg), Bigloo, Scheme48/scsh, Kawa, SISC, SCM, NexJ, KSi, RScheme, XLisp, Rep, VX, SXM, Inlab return `+inf.0` in both cases.
Elk, UMB, Oaklisp raise an exception in both cases.
Scheme 7 returns the wrong answer in both cases.
!SigScheme, Shoe, !TinyScheme, Dream, BDC, Owl Lisp don't support `log`.
Scheme 9 apparently goes into an infinite loop in both cases.
I don't know how to shut off floating-point traps in MIT.R5RS and draft 6 of R7RS don't say what `(log 0.0)` and `(log 0)` return. R6RS requires `-inf.0` and an exception respectively. The proposal is to say that `(log 0.0)` returns `-inf.0` on systems that have `+inf.0`, and that `(log 0)` is an error.
In Racket, Gambit, Chicken (with the numbers egg), Guile, Chibi, Chez, !Ikarus/Vicare, Larceny, Ypsilon, Mosh, !IronScheme, STklos, Spark, `(log 0.0)` returns `-inf.0` and `(log 0)` raises an exception.
Gauche, MIT, Chicken (without the numbers egg), Bigloo, Scheme48/scsh, Kawa, SISC, SCM, NexJ, KSi, RScheme, XLisp, Rep, VX, SXM, Inlab return `-inf.0` in both cases.
Elk, UMB, Oaklisp raise an exception in both cases.
Scheme 7 returns the wrong answer in both cases.
!SigScheme, Shoe, !TinyScheme, Dream, BDC, Owl Lisp don't support `log`.
Scheme 9 apparently goes into an infinite loop in both cases.