Greek mathematics from the sixth century BCE to the fourth century CE is represented by the work of, e.g., Pythagoras; Proclus; Thales; Democritus; Hippocrates of Chios; Theaetetus; Plato; Eudoxus of Cnidus; Aristotle; Euclid; Eratosthenes; Apollonius; Ptolemy; Heron of Alexandria; Diophantus; Pappus.