DEFINITION MODULE CharClass; (* Classification of values of the type CHAR *) PROCEDURE IsNumeric (ch: CHAR): BOOLEAN; (* Returns TRUE if and only if ch is classified as a numeric character *) PROCEDURE IsLetter (ch: CHAR): BOOLEAN; (* Returns TRUE if and only if ch is classified as a letter *) PROCEDURE IsUpper (ch: CHAR): BOOLEAN; (* Returns TRUE if and only if ch is classified as an upper case letter *) PROCEDURE IsLower (ch: CHAR): BOOLEAN; (* Returns TRUE if and only if ch is classified as a lower case letter *) PROCEDURE IsControl (ch: CHAR): BOOLEAN; (* Returns TRUE if and only if ch represents a control function *) PROCEDURE IsWhiteSpace (ch: CHAR): BOOLEAN; (* Returns TRUE if and only if ch represents a space character or a format effector *) END CharClass.