Deduction

neighbour 1: Hi you just move here?
neighbour 2: Ya I just move here, this place is quite nice.
neighbour 1: What is your occupation?
neighbour 2: I am professor at university. I teach deduction.
neighbour 1: Deduction? Whats that?
neighbour 2: Ok like this, I'll give you an example. I saw you've got a dog house, so I can say that you keep a dog as pet.
neighbour 1: Ya its true.
neighbour 2: That fact shows that you have a family.
neighbour 1: Ya that is true.
neighbour 2: So the conclusion is you got a wife.
neighbour 1: Wow. All true.
neighbout 2: Its all call deduction.

that evening....

neighbour 1: I just chit chat-ed with the new neighbour
neighbour 3: Oh, what's his job?
neighbour 1: He is a professor who teaches deduction.
neighbour 3: Deduction? What's that?
neighbour 1: Ok i'll give you an example. You keep a dog as pet?
neighbour 3: No!
neighbour 1: Aiseyman...