Tom DeMarco, "Controlling software projects", 1982, Prentice Hall, page 75
I began this chapter with an analogy, the specification of a solid figure by three-view projection. Applying some of the terms used in the analogy, we now can consider each of the components of the requirement model a projection onto a different space. So, the functional model - the partitioning into constituent functions and inter-function interfaces - can be thought of as a projection onto function space; the retained data model, a projection onto information space; and the state transition model, a projection onto state space.
It is a miracle how quick the "computer science" loses critical knowledge and how persistent it tries to reinvent a bicycle (with more and more quadratic wheels at each new attempt).