Tammo Freese <tammo.freese / offis.de> writes: > After the Pickaxe Book, first print, p. 320 ... > However, as the results of the code in the pickaxe book are generated > by running the code (aren't they?), 1.6.0 seems to have the correct(?) > behaviour (returning NaN). I just ran this again on my box here (ruby 1.6.2 (2001-02-02) [i686-linux]): a = -1.0 # => -1.0 a.nan? # => false a = Math.log(a) # => NaN a.nan? # => true So, there seems to be a difference between a Linux box and a Windows/cygwin box. Anyone any ideas? Dave