load(functs); inverts evenp and oddp



There are bunches of functions that can be accessed
in common lisp, and maybe it is worth making a list
of them somewhere.
Like ?evenp(), ?oddp(), ?logand(), ...

My guess is that renaming their functionality is counterproductive:
?logand  will still be there, so calling it bitwise_and doesn't
really help.

If you add symbolic capabilities, maybe you have a better case.
That is  evenp(x)  could simply call ?evenp if x is an integer.
But

is evenp(2*n)   --->    is (integerp(n))
is oddp(x+45)   --->     is (evenp(x))

etc for simplification.




Robert Dodier wrote:

> On 5/3/06, Stavros Macrakis <macrakis at gmail.com> wrote:
>
>> Eventually, I think logand etc. should all become simplifying 
>> functions, so
>> that logand(0,x)=>0, logand(-1,x)=>x, logand(x,x)=>x, etc. 
>

logand (?  , interval) ???

>>
>
> Agreed, but when we get to that, let's take the opportunity to change the
> names from logand, logor, and logxor to bitwise_and, bitwise_or, and
> bitwise_xor.
>
> logfoo is confusing on two counts; log is short for logarithm, a function
> which plays a larger role in Maxima than bitwise operations, and
> "logical" isn't a very good description anyway -- these functions are
> just for bit twiddling, and have nothing to do with symbolic true / 
> false.
>
> FWIW
> Robert
>
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