It's claimed in Wikipedia that:
F-bounded quantification or recursively bounded quantification, introduced in 1989, allows for more precise typing of functions that are applied on recursive types. A recursive type is one that includes a function that uses it as a type for some argument or its return value
Here's the article which Wikipedia refers to, and F-bounded quantification is introduced in that article in following fashion:
F-bounded quantification is a natural extension of bounded quantification that seems particularly useful in connection with recursive types.
My question is - why though it's F-bounded, what does "F" stands for in this particular context?