0.3 is an "unstable" version, meaning that the API is subject to change. Once version 0.4 is released, the public terms and their semantics are guaranteed not to change for any 0.4.n micro-version. Many public terms are not needed by the user-developer, but are made public for testing purposed. Public terms commonly invoked by the user-developer are considered keywords, some of which are abstract to be defined at design-time. Keywords also include properties. Named parameters that are more typically supplied as positional