He makes a lot of assertions, and yet doesn’t actually show in the linked Web page how “mathematics proves beyond the shadow of doubt that evolutionism is nonsense.”
He also seems to be unclear about which aspects of evolution he is trying to refute. Evolution itself (the emergence and spread of new genes in a population) is an observable fact - in the small scale observable in a human lifetime, as anyone who reads about antibiotic-resistant bacteria, or the development of copper-resistant plants around old mines will know.
So is he trying to disprove that speciation doesn’t occur? That the mechanism isn’t Darwininian ‘survival of the fittest’ selection pressure”? Or is he arguing about the origins of life (which is rather different to the evolution of life and should not be conflated).
I suspect that the author is a very good mathematician who is a bit confused about evolutionary biology.