public Parser paragraphStart() {
        if (paragraphStartParser == null) {
           FutureParser future = scoped("paragraphStart");
           paragraphStartParser = future;
           future.setParser(
               sequence(
                   choice(
                       token("SOURCE-COMPUTER"),
                       token("OBJECT-COMPUTER"),
                       token("SPECIAL-NAMES"),
                       token("REPOSITORY"),
                       token("CONSTRAINTS"),
                       token("CLASS-ATTRIBUTES"),
                       token("ASSEMBLY-ATTRIBUTES"),
                       token("FILE-CONTROL"),
                       token("I-O-CONTROL"),
                       token("CLASS-CONTROL")
                   ),
                   token(".")
               )
           );
        }

        return paragraphStartParser;
    }