Parallel (geometry) as a pair of straight lines in a plane which do not meet appears as Definition 23 in Book I of Euclid's Elements. Alternative definitions were discussed by other Greeks, often as part of an attempt to prove the parallel postulate. Proclus attributes a definition of parallel lines as equidistant lines to Posidonius and quotes Geminus in a similar vein. Simplicius also mentions Posidonius' definition as well as its modification by the philosopher Aganis. At the end of the nineteenth century, in England, Euclid's Elements was still the standard textbook in secondary schools. The traditional treatment of geometry was being
Antiochus (father of Seleucus I Nicator) numerous descendants through his son from the 3rd century BC until the 5th century AD and possibly beyond. Antiochus (father of Seleucus I Nicator) Antiochus (Greek: Ἀντίοχος; fl. 4th century BC) was a Macedonian man who lived during the time of Philip II of Macedon (ruled 359-336 BC). He originally came from Orestis, Macedonia. Antiochus served as an officer under Philip II, and gained distinction as a military general. Antiochus was from an upper noble family. His father was probably called Seleucus, his brother was called Ptolemy and he probably had a nephew called Seleucus. Antiochus married a Macedonian woman