Answer:
- Euler's Totient.
Explanation:
'Euler's Totient' theory demonstrates the number of relatively prime positive integers which are lesser than n. It is elucidated as the 'totality of numbers that are co-prime'. A co-prime number is described as the set of integers that do not possess any common factor other than 1. Such numbers only have 1 as their highest common factor and also characterized as 'relatively prime' numbers. Thus, Euler's Totient theory states the overall number of relatively prime positive numbers up to n.
