official "zerop"?



Lisp has a function zerop which returns true for 0 or 0.0 .
Does Maxima have a function which returns true for all
kinds of zeros, i.e. bigfloats of any precision, as well as 0, 0.0e0, 
0.0d0 ?

This kind-of works,   is(equal(0,0.0b0))  but only at the cost
of converting 0.0b0 to a rational number..

And this works, too:

  zerop(x):= is( x=0 or x=0.0 or bfloatp(x) and ?cadr(x)=0)