Matematik

Givet: två entiteter.
Problem: är de lika?

Att lösa problemet kallas "Matematik".  Ett annat ord är "problemlösning".

Another example

From physics (thermomodynamics) we have the rule for ideal gases:
It says that energy is equal to energy. This is certainly a truism. Maybe it is the definition of temperature and entropy.

According to some of my sources,.physical laws, that are not truisms, are unable to verify. "Everyone knows it is true.".

Is it true?

Yes it is, if it is a tautology.

A tautology (from the Greek word ταυτολογία) is a formula which is true in every possible interpretation

Most mathematical theorems are tautologies.  Nevertheless it is not obvious to everyone.