(related to Proposition: Nth Powers)
By hypothesis, \(n\in\mathbb Z\) is an integer. Note that, together the with the multiplication operation of real numbers "\(\cdot\)", the set \((\mathbb R,\cdot )\) is an Abelian group. Therefore, the \(n\)-th power function \(f:x\to x^n\) is well-defined as an exponentiation of \(x\in\mathbb R\).