Elena Lucrezia Cornaro Piscopia, a 17th-century Venetian philosopher and mathematician, was the first woman to obtain a PhD. At this time, Italian society was passionate about debates on philosophy and mathematics, considered inseparable branches of knowledge. Mathematical logic problems are a clear example.

Can you solve this one?

I climbed a cherry tree

with cherries on it. 

Cherries I did not pick;

cherries I did not leave:

how many cherries were there?