A guy sees his new neighbor out in his backyard, so he decides to get acquainted.
After introductions, he asks the new neighbour what he does for a living.
The new neighbor says, "I'm a professor." The first neighbour then asks, "Oh yeah, what do you teach?"
"Logic," the professor responds.
"What is that?" the neighbor inquires.
"Well, let me see if I can give you an example...you have a dog, right?"
"Yeah, that's right," neighbour responds.
"And you have children too, right?" says the professor.
"Wow, right again!" exclaims the neighbour.
"So, then you must be married and that would make you a heterosexual, right?'' proclaims the professor.
"Unbelievable, you're absolutely correct. How do you know all this about me?"
"Well," the professor says, "I observed there was a dog house in your backyard, so you must have a dog.
I also saw bicycles next to your garage, so you must have children.
And if you have children, you are probably married and if your married, you are most likely heterosexual... it was all logical!"
The next afternoon, the neighbour runs into his old friend.
His friend asks if he has met the new neighbour.
The man says that he met him yesterday.
"What's he like?"
"Well," the man says, "he's nice and he is a professor of logic."
"Oh," says the friend, "what's logic?"
"Maybe I can give you an example. Do you have a dog house?"
"Why, no, I do not," responds the friend.
"Well, then," proclaims the man, "you must be gay!"