function
(/ & xs)
Returns the quotient of xs. If xs is empty, returns 1. If xs has
one value x, returns the reciprocal of x. Otherwise return the
first value of xs repeatedly divided by the remaining values.
(/ 0)
# => inf
(/ 1 2 3)
# => 0.166667
(/ 2)
# => 0.5
(/)
# => 1