In the few cases where there is a difference, this tutorial describes what the author calls "Classical F", the version that runs under the GUI F_World. The differences are described in an appendix.
The F language is described more fully in the book, Programmer's Guide to F, by Brainerd, Goldberg and Adams. Since that book is intended to serve both as a tutorial and as a reference, it includes more detail on some topics early in the book than necessary for a beginner. Therefore the organization of this tutorial is somewhat different, although it is essentially the same in overall outline. Also, a number of topics that are more advanced or not important for numerical work are omitted for the sake of brevity and simplicity. (An appendix provides a list of the most important elements of F that are omitted.)
The table of contents may be viewed here.