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.
Pipe Size. The pipe stub-outs under your sink are branch pipes that connect to 3/4-inch main pipes, and they always have a diameter of 1/2 inch.Plumbers conform to this standard whether installing copper, chlorinated polyvinyl chloride (CPVC) or polybutylene (PB) pipes.he rough-in plumbing to a sink consists of two water pipes -- one hot and one cold -- that terminate with shut-off valves. When you install the sink faucet, you connect it to the valves with flexible hoses.