IF 'MEASURE_SCHEMA.SI_UNIT' IN  TYPEOF(u) THEN
    RETURN(string_for_SI_unit(u));
ELSE
    IF  'MEASURE_SCHEMA.CONTEXT_DEPENDENT_UNIT' IN  TYPEOF(u)
    THEN
        RETURN(u\context_dependent_unit.name);
    ELSE
        IF  'MEASURE_SCHEMA.CONVERSION_BASED_UNIT' IN  TYPEOF(u)
        THEN
            RETURN(u\conversion_based_unit.name);
        ELSE
            IF 'ISO13584_IEC61360_DICTIONARY_SCHEMA'
                +'.NON_SI_UNIT' IN TYPEOF(u)
            THEN
                RETURN(u\non_si_unit.name);
            ELSE
                RETURN('name_unknown');
            END_IF;
        END_IF;
    END_IF;
END_IF;