Ptolemy I Soter rivals after Alexander's death. For example, Arrian's account of the fall of Thebes in 335 BC ("Anabasis" , a rare section of narrative explicitly attributed to Ptolemy by Arrian) shows several significant variations from the parallel account preserved in Diodorus Siculus (17.11–12), most notably in attributing a distinctly unheroic role in proceedings to Perdiccas. More recently, J. Roisman has argued that the case for Ptolemy's blackening of Perdiccas and others has been much exaggerated. Ptolemy personally sponsored the great mathematician Euclid. He found Euclid's seminal work, the "Elements", too difficult to study, so he asked if there were an easier
Menelaus of Alexandria great circle arcs, which he named "trilaterals") and proves Menelaus' theorem on collinearity of points on the edges of a triangle (which may have been previously known) and its analog for spherical triangles. It was later translated by the sixteenth century astronomer and mathematician Francesco Maurolico. The lunar crater Menelaus is named after him. The titles of a few books by Menelaus have been preserved: Menelaus of Alexandria Menelaus of Alexandria (; , "Menelaos ho Alexandreus"; c. 70 – 140 CE) was a Greek mathematician and astronomer, the first to recognize geodesics on a curved surface as natural analogs of