Simplified Common Lisp reference
<
Symbol class: Mathematics, Arithmetics, Logic and Comparisons
Syntax:
Symbol type: function
<numbers(one or more) => T or NIL
Argument description:
numbers numeric values

< function compares numbers according to "less than" predicate. Each (overlapping) pair of the numbers is compared by it. The result is true if all compared pairs satisfy comparison. Note that complex numbers cannot be compared.

(< 1 2) => T
(< 2 1) => NIL
(< 2 2.001) => T
(< 2 2) => NIL
(< 1234567890123456789 9876543210987654321) => T
(< 1 2 3 4 5) => T
(< 1 2 4 3 5) => NIL
(< 1 2 4 4 5) => NIL
(< 3/4 7/9) => T
(< 5) => T
Function indexFull documentation for < (HyperSpec)