simplifying predicates



We've talked about making simplifying versions of integerp, oddp, and ...; see
thread starting at

  http://www.math.utexas.edu/pipermail/maxima/2010/021502.html

We could define simplifications for the nounforms of integerp and friends. This would work
something like:

 (%i2) integerp(x);
 (%o2) false

The nounform simplifies:

 (%i25) 'integerp(x);
 (%o25) integerp(x)

 (%i26) [subst(x = 42,%), subst(x = sqrt(2),%), subst(x = log(42),%)];
 (%o26) [true,false,integerp(log(42))]

Maxima doesn't know that log(42) isn't an integer. So it goes. 

 (%i27) 'integerp(42);
 (%o27) true

Maybe this scheme (especially %o27) isn't all that clear to users?  Other functions work this way 
(integrate and sum, I think).

--Barton