Complex sentence: Most mathematicians however find it difficult to visualize a well-ordering of, for example, the set R of real numbers; in 1904, Gyula Kőnig claimed to have proven that such a well-ordering cannot exist.
Split into simpler sentences: Most mathematicians however find it difficult to visualize a well-ordering of, for example, the set R of real numbers. In 1904, Gyula Kőnig claimed to have proven that such a well-ordering cannot exist.