Define a function that checks whether a given number is prime. Your primal check does not have to be efficient; any algorithm you can think of will do. In case you have forgotten, a prime number is a...

Define a function that checks whether a given number is prime. Your primal check does not have to be efficient; any algorithm you can think of will do. In case you have forgotten, a prime number is a natural number strictly greater than 1 and with no positive divisors other than 1 and itself. Write another function that generates a vector with all natural numbers less or equal to a first number and starting from another. By default it should start from 1. Create a third function that given a vector of numbers outputs another vector containing all the prime numbers it found in its input. Use these three functions to create a program that prints out all prime numbers less or equal to a number chosen by the user (print, for instance, 15 primes per line). Note: In principle, you do not need any vectors to print these prime numbers; obviously, these extra functions have been added for the sake of the exercise.