The Poisson distribution is supported on the non-negative integers \(\{0, 1, 2, \ldots\}\).
# S3 method for class 'poisson_dist'
sup(x)A countable_set object with lower bound 0.
sup(poisson_dist(5))
#> <countable_set>
#> Public:
#> clone: function (deep = FALSE)
#> initialize: function (lower = 0L)
#> lower_bound: 0