Age wrote: ↑Sun Mar 17, 2024 4:36 am
And, what is the difference between 'natural numbers' and 'numbers'?
Natural numbers can be reached through consecutive succession: 1,2,3,... , except for 0 which can only be axiomatized to be a natural number.
The natural numbers are closed under addition and multiplication. So, adding two natural numbers or multiplying them results again in a natural number.
Natural numbers are not closed under substraction. For example, 3 - 5 = -2, is not a natural number but an integer.
Natural numbers are also not closed under division. For example, 3/10 = 0.3, which is not a natural number but a rational.
With additional operations, you can reach new kinds of numbers, until you reach the set of computable numbers, which is a subset of the real numbers, most of which can however not be reached in any computable way.