Programs would begin with a recall. End with a joke. Variable declarations would read like "Notation: n in Integers". The program body would be divided into Lemmas and Theorems

]]>so the question is about "esoteric things" in general which can be used in such.

like chaotic logistic maps, unlambda calculus, arithmetic with n-dimensional branes.

"those things".

languages themselves could be nice but they are rarely other than hard to read.

if you know some which stand out I would really appreciate that

The keyword to describe such is esoteric system.

As a beginner, I lack knowledge. I'd like to know any methods, functions, maps, anything strange in programming and/or maths.

Anything which doesn't seem to make any sense or is counter-intuitive.

What madness have you faced so far?

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