At the time the "Mayo" case was decided, there was some uncertainty over whether it applied only to natural principles (laws of nature) or more generally to patent eligibility of all abstract ideas and general principles, including those involved in software patents. The "Alice" decision confirmed that the test was general. The "Alice" case involved patents on electronic methods and computer programs for financial-trading systems on which trades between two parties who are to exchange payment are settled by a third party in ways that reduce the risk that one party performs while the other does not. The patents cover what amounts to a computerized escrow arrangement.