An expression entered by a user to set a limit variable for a numerical range may be received in a computer system. The expression signifies to the user that the numerical range is unlimited. The limit variable can only be set with a numerical value. The limit variable is set with a first numerical value that is within a predetermined extreme portion of the numerical range. A command to display a limit variable for a numerical range may be received in a computer system. The limit variable is set with a numerical value. If the numerical value is within a predetermined extreme portion of the numerical range, an expression is displayed to a user that signifies to the user that the numerical range is unlimited. If the numerical value is not within the predetermined extreme portion of the numerical range, the numerical value is displayed to the user.