description:
log+1 ket
log+1[t] ket
logarithm of 1 + x
if x <= 0, return 0
if t is None, return math.log(1 + x) (ie, base e)
else, return math.log(1 + x, t) (ie, base t)
examples:
log+1 0|a>
0|a>
see also: