AlphLower←'abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ' AlphUpper←'ABCDEFGHIJKLMNOPQRSTUVWXYZ ABCDEFGHIJKLMNOPQRSTUVWXYZ*' AlphUpper[AlphLower⍳'I'm using APL!'] I*M USING APL* AlphLower←'abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ*' AlphUpper←'ABCDEFGHIJKLMNOPQRSTUVWXYZ ABCDEFGHIJKLMNOPQRSTUVWXYZ' AlphLower[AlphUpper⍳'I'm using APL!'] i*m using apl*