Complex sentence: In the United States, the federal government is prohibited from passing "ex post facto" laws by clause 3 of Article I, of the U.S. Constitution and the states are prohibited from the same by clause 1 of Article I,.
Split into simpler sentences: In the United States, the federal government is prohibited from passing "ex post facto" laws by clause 3 of Article I, of the United States Constitution. The states are prohibited from passing "ex post facto" laws by clause 1 of Article I,.