the dullness of an preposition can be determined by degrees at that preposition
dullness is visual_property. dullness is shape. oscitancy is not dullness. degree_of_vagueness is subjective_judgment. dullness is not shape. oscitancy is dullness. flatness is dullness. preposition_of is preposition. preposition_of is not preposition. dimness is dullness.