pop and push?



Hi,
while updating the manual section on Lists, I noticed that the pop() and 
push() functions described in the manual do not seem to make part of 
core Maxima anymore:

    (%i2) pop([1,2,3]);
    (%o2) pop([1,2,3])

    (%i3) push(0, [1,2,3]);
    (%o3) push(0, [1,2,3])

have they been moved to some additional package, or were they removed?

Cheers,
Jaime