Collatz conjecture possibly solved

The Collatz conjecture is an unsolved conjecture in mathematics named after Lothar Collatz, who first proposed it in 1937.

Gerhard Opfer from the University of Hamburg claims to have solved the Collatz Conjecture aka the Colatz 3n+1 Problem.
Here is a link to the pdf. http://preprint.math.uni-hamburg.de/public/papers/hbam/hbam2011-09.pdf

Take any natural number n. If n is even, divide it by 2 to get n / 2, if n is odd multiply it by 3 and add 1 to obtain 3n + 1. Repeat the process (which has been called “Half Or Triple Plus One”, or HOTPO[4]) indefinitely. The conjecture is that no matter what number you start with, you will always eventually reach 1. The property has also been called oneness.

Start with a positive number n and repeatedly apply these simple rules:

If n = 1, stop.
If n is even, divide n by 2.
If n is odd, multiply n by 3 and add 1.
In 1937, Lothar Collatz asked whether this procedure always stops for every positive starting value of n. If Gerhard Opfer is correct, we can finally say that indeed it always stops.

Gerhard Opfer from the University of Hamburg claims to have solved the Collatz Conjecture aka the Colatz 3n+1 Problem.
Here is a link to the pdf. http://preprint.math.uni-hamburg.de/public/papers/hbam/hbam2011-09.pdf