::= | ::= "REM" | "PRINT" | "IF" "THEN" | "GOTO" | "INPUT" | "LET" "=" | "GOSUB" | "RETURN" | "END" ::= | ::= " " .. "~" ::= | "," ::= | ::= | "," ::= | "+" | "-" ::= | "*" | "/" factor ::= "-" | "+" | | | "(" ")" ::= "A" .. "Z" ::= | ::= "0" .. "9" ::= "<" | "=" | ">" | "<=" | "<>" | ">=" ::= '"' '"'