Gabriel was a Lisp programmer when he formulated the concept in 1989, presenting it in his essay "Lisp: Good News, Bad News, How to Win Big".
理查·加百烈當時是一名Lisp程式設計師，1989年在他的"Lisp: Good News, Bad News, How to Win Big"（Lisp：好消息，壞消息，如何贏得大）一文中提出這個概念。