#### 4.1.5 Conditionals

— syntax: if <test> <consequent> <alternate>
— syntax: if <test> <consequent>

> Syntax: <Test>, <consequent>, and <alternate> may be arbitrary expressions.

> Semantics: An ‘`if`’ expression is evaluated as follows: first, <test> is evaluated. If it yields a true value (see section see Booleans), then <consequent> is evaluated and its value(s) is(are) returned. Otherwise <alternate> is evaluated and its value(s) is(are) returned. If <test> yields a false value and no <alternate> is specified, then the result of the expression is unspecified.

>     (if (> 3 2) 'yes 'no)                  ==>  yes
>          (if (> 2 3) 'yes 'no)                  ==>  no
>          (if (> 3 2)
>              (- 3 2)
>              (+ 3 2))                           ==>  1