For natural numbers m, nep arbitrary, it is valid: mn is defined, that is, multiplication is in fact an operation in Naturals

In the context of natural numbers (often denoted as N), multiplication is indeed a defined operation. Natural numbers are the set of positive integers starting from 1 and continuing indefinitely (1, 2, 3, 4, ...). Multiplication of natural numbers is a binary operation, meaning it takes two natural numbers as inputs and produces another natural number as its output. For any two natural numbers "m" and "n," the result of multiplying them together, denoted as "mn," is a natural number. For example: 2 times 3 equals 6 (2 * 3 = 6), where 2 and 3 are natural numbers, and the result 6 is also a natural number. 4 times 5 equals 20 (4 * 5 = 20), where 4 and 5 are natural numbers, and the result 20 is also a natural number. So, in the set of natural numbers, multiplication is a valid and well-defined operation.