equality predicates (was Re: [plt-scheme] fractions and decimals)

Robert Bruce Findler writes:
 > Actually, I think that integer? is, but positive? isn't:
 > 
 >   Welcome to MzScheme version 203.2, Copyright (c) 1995-2003 PLT
 >   > (integer? #f)
 >   #f
 >   > (positive? #f)
 >   positive?: expects argument of type <real number>; given #f

Oops, you're right, `number?', `complex?', `real?', `rational?', and
`integer?' are all general predicates.  Maybe I was thinking of
`exact?'.  This will simplify some of my code...

--dougo at ccs.neu.edu