1 wrong points here:-
Proof by tradition:- See 'proof by contraposition' – 7P is to forward arrow F.. Then how can right diagonal arrow 7R be the son?
Or am I missing something here in the equation?

also, in 'by tradition' doesn't the end of the equation say Not R? when in fact the problem is that it is R?

1 wrong points here:-

Proof by tradition:- See 'proof by contraposition' – 7P is to forward arrow F.. Then how can right diagonal arrow 7R be the son?

Or am I missing something here in the equation?

also, in 'by tradition' doesn't the end of the equation say Not R? when in fact the problem is that it is R?

I'm pretty sure that's not an implication symbol.