// inherit. The first editor can display either a length, keyword,
// inherit or the numerator of the fraction, but the second can
// only display the denominator of the fraction.
StyleType type = styleProperty.getStandardDetails().
getSupportedStructure();
StyleFractionType fractionType = null;
if (type instanceof StyleFractionType) {
fractionType = (StyleFractionType) type;
} else if (type instanceof StyleChoiceType) {
StyleChoiceType choice = (StyleChoiceType) type;
List types = choice.getTypes();