On the origin of the fork notation

A student posts: 

    Dr. Everest, I just caught the fact that you developed the "fork" notation.

Good thinking, it is the most clear and simple of all 1:M relationship notations by far!

‑It occurred to me that maybe the profile of a badminton birdie was your inspiration?

Everest response:

    At the time when I did that (in a 1976 paper*, which became chapter 4 in my Database Management book, McGraw-Hill, 1986, §4.3.2, p.132) my idea came from trying to resolve the difference between the then dominant diagraming scheme of an arrow from parent to child (due to Charlie Bachman in a 1969 paper), and Nijssen drawing the arrow in the opposite direction to represent a function.  What I did was move Nijssen's arrow head to the other end of the arc and voila, a fork!

    

*Here is the reference (click on the title to get a copy of the paper):

Gordon C. Everest, "BasicData Structure Models Explained With A Common Example" Computing Systems 1976, Proceedings Fifth Texas Conference on Computing Systems, Austin, TX, 1976 October 18-19, pages 39-46. (Long Beach, CA: IEEE Computer Society Publications Office).  

            Original paper using a notation for relationship characteristics.  Thought to be the first to use what is now called a "fork" to represent multiplicity in a relationship.  An updated version appeared as Chapter 4 in Database Management:  Objectives, System Functions, and Administration, McGraw-Hill, 1986.