Complex sentence: In fact, Mojzesz Presburger proved in 1929 that there is an algorithm which decides for any given statement in Presburger arithmetic whether it is true or not.
Split into simpler sentences: In fact, Mojzesz Presburger proved in 1929 that Presburger arithmetic is decidable. In other words, there is an algorithm which decides for any given statement in Presburger arithmetic whether it is true or not.