LabLISP Guide

PROGN

PROGN accepts any number of any arguments - it just packs a sequence of forms. All the arguments are evaluated and the result of the last one is returned. The forms before the last one only show the side effects.

>(progn (print "a")         ; PRINT will print as side effect
        (print "b")
        (print "c")) 
"a"
"b"
"c"
"c"                         ; return value from the last PRINT

PROGN can be used in the cases, where only single form can be used, as in IF