Editing Xenocrates (section)

===Mathematics===
Xenocrates is known to have written a book ''On Numbers'', and a ''Theory of Numbers'', besides books on [[geometry]].{{sfn|Laërtius|1925|loc=§ 13, 14}} [[Plutarch]] writes that Xenocrates once attempted to find the total number of syllables that could be made from the letters of the alphabet.<ref>Plutarch, ''Quaest. Conviv.''</ref> According to Plutarch, Xenocrates result was 1,002,000,000,000 (a "[[myriad]]-and-twenty times a myriad-myriad"). This possibly represents the first instance that a combinatorial problem involving [[permutations]] was attempted. Xenocrates also supported the idea of "indivisible lines" (and magnitudes) in order to counter [[Zeno's paradoxes]].<ref>Simplicius, ''in Arist. Phys.''</ref>