The first European attempt to prove the postulate on parallel lines – made by Witelo, the Polish scientists of the 13th century, while revising Ibn al-Haytham's Book of Optics (Kitab al-Manazir) – was undoubtedly prompted by Arabic sources.
O primeiro intento europeo de probar o postulado das rectas paralelas – feito por Witelo, o científico polaco do século XIII, mentres revisaba o Libro de Óptica de Ibn al-Haytham (Kitab al-Manazir) – estaba sen dúbida inspirado por fontes árabes.