Re: parallel argument evaluation

[Robert Halstead <rhh@VX.LCS.MIT.EDU>]

    Yes, this is a good example, as was Tiedeman's.  But a very small 
    change to your example:

	(- (rand) (rand))

    makes even sequential programs unportable!  Sigh ... :-(

True, depending slightly, I suppose, as to whether you consider drawing
different elements out of the same statistical distribution to be a
violation of portability!  Seriously, though, if you have procedures
that, as a side effect, count the number of times they are called, or
perform similar side effects that may not even affect what is returned
directly as a value, evaluating arguments genuinely in parallel requires
a much tighter coding style than just evaluating them sequentially
according to some unspecified permutation...		-Bert