▁the ▁stack , ▁and ▁rep laces ▁it ▁with ▁" One ", ▁" L ess ", ▁or ▁" More ", ▁depending ▁on ▁whether ▁it ▁is ▁equal ▁to , ▁less ▁than , ▁or ▁greater ▁than ▁ 1 . ▁▁▁ ▁« ▁▁▁▁ ▁D UP ▁ 1 ▁== ▁▁▁▁ ▁« ▁D ROP ▁" One " ▁» ▁▁▁▁ ▁« ▁ 1 ▁< ▁" L ess " ▁" More " ▁IF TE ▁» ▁▁▁▁ ▁IF TE ▁▁ ▁» ▁ ▁CASE / TH EN / END ▁To ▁support ▁more ▁complex ▁conditional ▁logic , ▁R PL ▁provides ▁the ▁CASE / TH EN / END ▁structure ▁for ▁handling ▁multiple ▁exclusive ▁tests . ▁ ▁Only ▁one ▁of ▁the ▁branches ▁within ▁the ▁CASE ▁statement ▁will ▁be ▁executed . ▁ ▁The ▁basic ▁syntax ▁of ▁this ▁block ▁is : ▁▁▁ ▁CASE ▁▁▁▁ ▁condition _ 1 ▁THEN ▁if - condition _ 1 ▁END ▁▁▁▁▁ ▁... ▁▁▁ ▁condition _ n ▁THEN ▁if - condition _ n ▁END ▁▁▁ ▁if - none ▁▁ ▁END ▁ ▁The ▁following ▁code ▁illustr ates ▁the ▁use ▁of ▁a ▁CASE / TH EN / END ▁block . ▁ ▁Given ▁a ▁letter ▁at ▁the ▁bottom ▁of ▁the ▁stack , ▁it ▁rep laces ▁it ▁with ▁its ▁string ▁equivalent ▁or ▁" Unknown ▁letter ": ▁▁▁ ▁« ▁▁▁▁▁ ▁CASE ▁▁▁▁▁▁▁▁ ▁D UP ▁" A " ▁== ▁THEN ▁" Alpha " ▁END ▁▁▁▁▁▁▁ ▁D UP ▁" B " ▁== ▁THEN ▁" B eta " ▁END ▁▁▁▁▁▁▁ ▁D UP ▁" G " ▁== ▁THEN ▁" Gamma " ▁END ▁▁▁▁▁▁▁ ▁" Unknown ▁letter " ▁▁▁▁ ▁END ▁▁▁▁ ▁SW AP ▁D ROP