Complex sentence: After World War II, the diocese of Mukačevo in Transcarpathia was annexed by the Soviet Union, thus the diocese of Prešov included all the Greek Catholics that remained in Czechoslovakia.
Split into simpler sentences: After World War II, the diocese of Mukačevo in Transcarpathia was annexed by the Soviet Union. Then, the diocese of Prešov included all the Greek Catholics that remained in Czechoslovakia.