I encountered the following implication in a text book:
which I'm strugling to understand...
Being (a) = f(x,y), it can be derived integrating the first equation:
That's because f(x,x) := 0 by definition.
Therefore the initial implication does not make sense to me.
Does it sense to some you guys?
If yes, would you pls help me to understand/derive it?
Thanks!