4.2.3 Sequencing

Syntax:  (begin <expression1> <expression2> ...)

The <expression>s are evaluated sequentially from left to right, and the value(s) of the last <expression> is(are) returned. This expression type is used to sequence side effects such as input and output.

  (define x 0)

  (begin (set! x 5)
         (+ x 1))                  =>  6

  (begin (display "4 plus 1 equals ")
         (display (+ 4 1)))        -|  4 plus 1 equals 5
                                   =>  unspecified