I messed up with english :p direct and contrapositive and I miss the negation af all contrapositive is negation and switch the hypothesis and the conclusion
2011/11/24 Christian Grunfeld <christian.grunf...@gmail.com>: > 2011/11/24 R - elists <list...@abbacomm.net>: >> i think you are realistically confused about truly "negating something" >> >> english is not your native language is it? > > No, it is not ! I am not as good in english as you but I am very good > with maths and logic! > (I want someone jumps over R-elists who tried to discredited me based > on a language barrier like Karsten Bräckelmann jumped over me before!) > > Maths language is unique so if someone of you dont agree with me in > what follows I can give you lectures out of the list. > I think YOU are confused about "negating something" because negating > is not the only thing and it is NOT what I am doing ! > > given A -> B called direct problem or direct statment > there exists: > > converse: B -> A > inverse: ~A -> ~B > contrapositive: ~B -> ~A > > The direct and the inverse problem are logicaly equivalent. The same > between converse and contrapositive ! > > Here we are dealing with direct problem and inverse problem ! > > You say: lets assume all non spam > A (is spam) > B (mark as spam) > if an email is spam then mark it as spam (A->B) > > I say: lets assume all spam > ~A(is ham) > ~B(mark as ham) > if an email is ham then mark it as ham (~A -> ~B) > > both are logically the same and gives same results but with the second > aproach you need to train the system with a few mails (your contacts) > with the other you need tons of mails in Bayes DB and tons of running > code. >
