Zaratrusta returns from reflecting and finds Sofia writing with chalk on a smooth rock surface. Sofia had finished dancing, so when she saw Zaratrusta she asked her: "Do you know anything about algebra?", and she replied that she knows something.
She then writes in stone, a^2 + b^2 = c^2...
-That's easy, says Sofía, it's the Pythagorean theorem...
-but did you know about the difference between squares
*Mmmm no
-a is simple and this is written a^2-b^2 = (a + b)(a-b)
*you know other topics besides algebra, you only know some philosophy
-Yes, I was also surprised that you know more philosophy than me, but apart from algebra and philosophy, there is astronomy, physics, trigonometry, geometry and some chemistry...
*wow, could you show me some of that knowledge?, Zaratrusta says as he pulls out the notebook from him.
-Of course, let's start with physics...
That's how they left the topic, which Sofía put at the end "introduction to algebra and other topics"...

note: just a quick drawing, I've been working late, there will be no new work this Saturday, so I scheduled it for Sunday...