Can you solve it? The maths of Lviv

When the city was a world centre of mathematical thought

UPDATE: The solutions can be read here

Like many of you I've hardly been able to think about anything else these past ten days apart from the war in Ukraine. So today's puzzles are a celebration of Lviv, Ukraine's western city, which played an important role in the history of 20th century mathematics. During the 1930s, a remarkable group of scholars came up with new ideas, methods and theorems that helped shape the subject for decades.

The Lwow school of mathematics - at that time, the city was in Poland - was a closely-knit circle of Polish mathematicians, including Stefan Banach, Stanisaw Ulam and Hugo Steinhaus, who made important contributions to areas including set-theory, topology and analysis.