Axiom is  a general purpose Computer Algebra system. It is useful for research and development of mathematical algorithms. It defines a strongly typed, mathematically correct type hierarchy. It has a programming language and a built-in compiler.
Polybutylene is simply a type of plumbing material that was manufactured between the late 70's and early 90's. It is thought that it was installed in over 6 million homes during that time period.
A private branch exchange (PBX) operator is a person who operates a telephone switchboard. Switchboards are used by large businesses, such as hotels, to handle calls internally as well as receive incoming calls.t an organization that uses a PBX, the PBX operator is the first person callers hear when they make a call. The operator receives calls and routes them to appropriate departments, as well as handling short questions and requests for assistance.