Update

beauty.md

@@ -7,6 +7,7 @@ Beauty can perhaps be seen as a [heuristic](heuristic.md), a touch of intuition
 What is beautiful then? As stated, there is a lot of subjectivity, but generally the following attributes are correlated with beauty:
 
 - **[simplicity](minimalism.md)/[minimalism](minimalism.md)**, typically finding simplicity in complexity, e.g. a very short formula or algorithm that describes an infinitely complex [fractal](fractal.md) shape, a simple but valuable equation in physics (*e = m * c^2*), a short computer program that yields rich results ([demoscene](demoscene.md), [code golfing](golf.md), [suckless](suckless.md), [minimal viable program](minimal_viable_program.md), ...).
+- **deepness** -- if something starting very simple, e.g. a single small equation, leads to consequences that may be studied for millennia, for example [prime numbers](prime.md).
 - **generality**, i.e. if a simple equation can describe many problems, not just a specific case.
 - **lack of exceptions**, i.e. when our equation works without having to deal with special cases (in programming represented by `if-then` branches).
 - **[symmetry](symmetry.md)**, i.e. when we can e.g. swap variables in the equation and get some kind of opposite result.