Why is Pythagoras Theorem a theorem and not a mathematical law ?
In mathematical logic, a theorem is a type of abstract object, one token of which is a formula of a formal language which can be derived from the rules of the formal system that is applied to the formal language; another token of which is a statement in natural language, that can be proved on the basis of explicitly stated or previously agreed assumptions.
Theorems are often indicated by several other terms. The actual label “theorem” is reserved for the most important results, whereas results which are less important, or distinguished in other ways, are named by different terminology, including law, proposition, lemma, corollary, claim, identity, rule, principle and converse.
