Functions are a bit of code that you can use again and again, just by using its name like any other command. In SmileBASIC, functions come in 3 forms: *No values returned (no parenthesis) DEF HI ?"Hi!" END *1 value returned (yes parenthesis, must include RETURN [value] somewhere) DEF E() RETURN 2.7182818 END *2 or more values returned (no parenthesis but with an OUT, no RETURN) no space 4 this