Round each number in interval X towards -Inf.
Accuracy: The result is a tight enclosure.
floor (infsup (2.5, 3.5)) ⇒ ans = [2, 3] floor (infsup (-0.5, 5)) ⇒ ans = [-1, +5]
See also: @infsup/ceil, @infsup/round, @infsup/roundb, @infsup/fix.
Package: interval