What did/would you say when approached by recruiters from Moss@d?
Never heard of it and am unable to find any information on it.
Oh, I get it now (if the leetspeak was to reduce Googleability, I think it's working). I was never approached by them. I doubt a position will be found there that suits my personality, but I wouldn't rule out anything a priori - all depends on what the position would require from me and how interesting and lucrative it is.
@augustocroppo - You still seem to assume that for every person X and statement Y exactly one of "X believes that Y" and "X believes that not Y" is true, and that "X believes that Y" is the same as "X believes that it is possible that Y". This is simply incorrect and no kind of logic argument can change that.
The word "believe" is pretty fuzzy and the accurate concept we need to consider is subjective probability. For every person X and statement Y, X has a given probability p assigned for Y, even if he does not explicitly quantify it. We generally understand "X believes that Y" to mean "X assigns a high probability to Y", let's say >0.9. So if 0.1<p<0.9 then X believes neither Y nor not Y; and if 0<p<0.1, then X believes not Y but still believes Y is possible.
Let's simplify the Santa Claus example by agreeing that "a Santa Claus" means "a person wearing red clothes living in the north pole". Consider the following discussion:
Q: Do you believe that a Santa Claus exists?
A: No, in fact I believe that a Santa Claus does not exist.
Q: Is it possible that a Santa Claus exists?
A: Yes.
Q: Why?
A: It is not that cold in the north pole, someone could live there if he wanted, and red clothes are easy to come by.
Q: If so, why do you believe no Santa Claus exists?
A: Because I don't see any reason why someone would want to go live in the north pole. Hence, it is unlikely anyone actually did that.
The answerer very consistently holds both the belief that a Santa Claus could exist (in the modal sense) and that no Santa Claus exists (as a contingent fact).
The same thing can happen with any other statement - I could believe it will rain tomorrow (since the forecaster said so) and that it is possible it will not rain tomorrow (since there certainly are sunny days, and the forecaster doesn't always get it right), etc. There is nothing special about statements asserting the existence of something; those have a subjective probability like any other statement, and one could give any kind of evidence or argument to establish his subjective probability.
Your set notation is still messed up. B ≠ D means that B and D are unequal (there is an element in one which is not in the other; there could still be an element common to both), not that they are disjoint (have no common element).