Simplified Common Lisp reference
floor
Symbol class: Mathematics, Arithmetics, Logic and Comparisons
Syntax:
Symbol type: function
floornumberdivisor => quotient (numeric value), remainder (numeric value)
Argument description:
number number
divisor non-zero real number, default is 1

FLOOR function returns two values, the first is result of dividing number by divisor and truncating toward negative infinity. Second result remainder that satisfies equation: quotient * divisor + remainder = number.

(floor 10) => 10, 0
(floor 10.3 2) => 5, 0.3000002
(floor 3/4) => 0, 3/4
(multiple-value-list (floor 20 7)) => (2 6)
Function indexFull documentation for floor (HyperSpec)