Sentence:  The traditional term, from ancient Greek theory, for the diatonic pythagorean semitone is 'limma'; and for the larger, chromatic semitone, ‘<WSD>apotome</WSD>'. / The oldest extant fretting formula, that of the ninth-century theorist Al-Kindi for the ud" (the Arabic lute), is pythagorean. It calls for five frets, to make the following succession of semitones down from nut: limma, apotome, limma, apotome''', limma. 
Meaning of the word marked with <WSD> tags:  The remaining part of a whole tone after a smaller semitone has been deducted from it; a major semitone.