In a conversation with my friend and mentor, Richard E. Geis - winner of thirteen Hugos; and editor and publisher of several incarnations of Science Fiction Review; and author of over one hundred novels - I came up with a new literary term. The term is equel. What does it mean?
New scientific theories, or interpretations of those theories, lead to changes in our vocabulary, in our lexicography, if you will. What I call quantum bifurcation theory, what is commonly known as the Everett-Wheeler, or the Many Worlds Interpretation of Quantum Mechanics, gives rise to a new literary term for a story set in a universe wherein the author assumes that Everett’s Interpretation is by-and-large correct. That term is equel. If two events happen at the same time and led to two stories with different events from that point forward, the older terms of sequel and prequel are not viable in this instance. I therefore propose a new literary term: equel.
The definition: An equel is a fictional story that is happening as a result of a quantum bifurcation of events. If you have one quantum pathway choice in one story and another in a different story then you have neither a sequel nor a prequel, but a story that occurs at the same time, and that makes it an equel, and that is a new literary term.