EN
Set theory, which had had its root in the works of Georg Cantor towards the end of the 19th century, reached university halls already at the beginning of the 20th century. First lectures at Polish universities were delivered by Stanisław Zaremba in Cracow (1911/1912) and Wacław Sierpiński in Lvov (1909/1910). Preserved notes from Zaremba’s lectures and Sierpiński’s course book enabled comparisons. set theory was for Zaremba a tool in accurate capturing of some properties of real numbers and for Sierpiński it was already an independent theory, focused on the notions of power and order.