Simplified Common Lisp reference
cond
Symbol class: Functions, Evaluation, Flow Control, Definitions and Syntax
Syntax:
Symbol type: macro
condvariants => an object
Argument description:
variants list of test and code variants

COND macro is used for branching. Variants are tested sequentially from the top. See also IF, CASE.

(cond ((> 3 4) "variant 1")
      ((> 4 2) "variant 2")
      (t "always valid variant")) => "variant 2"
Function indexFull documentation for cond (HyperSpec)