This advanced tutorial helped me https://www.ele.uri.edu/faculty/vetter/Other-stuff/vi/009-index.html https://www.ele.uri.edu/faculty/vetter/Other-stuff/vi/009-

This advanced tutorial helped me https://www.ele.uri.edu/faculty/vetter/Other-stuff/vi/009-index.html https://www.ele.uri.edu/faculty/vetter/Other-stuff/vi/009-in.... I have not found many advanced vi/m tutorials, I wish there were more. hth