 Just as signification corresponds most closely – though not exactly – to contemporary ideas of meaning or sense, so supposition corresponds in some ways to modern notions of reference, denotation and extension. The comparison is far from exact, however. One major difference is that the medievals distinguished many different modes (modi) of supposition. Despite the difference between different authors' semantic theories, particularly as they developed over the centuries, there is a remarkable consistency in the terminology and interrelation of the different modes.