Article I Section 17 Pennsylvania Constitution
Article I Section 17 Constitution of the Commonwealth of Pennsylvania is about Ex Post Facto Laws; Impairment of Contracts. Article I is titled Declaration of Rights, it has a preamble and 29 sections.
Ex Post Facto Laws; Impairment of Contracts
No ex post facto law, nor any law impairing the obligation of contracts, or making irrevocable any grant of special privileges or immunities, shall be passed.