Math !

How to have fun while travelling in a jam packed local train.

1) Stand at the door. Let the breeze hit your face.

2) Hum your favorite song.

3) Take the most fundamental mathematical formulae ( MF2 ), dress them up into some hypothetical situation and see if it stands.

So (+) * (+) = (+) , (+) * ( - ) = ( - ) and ( - ) * ( - ) = ( + ), eh? Fundamental indeed. For dressing them up into a neat hypothetical something, I introduce a buyer, (B) and a seller (S). BullShit? *Grin* I know. *Grin* . Anyways, a ( + ) for a buyer or a seller would be a profit in terms of money, good product or the outcome of the business, nai? And the ( - ) for both B & S would be a loss in terms of all those above mentioned. Suppose B & S does this business one day and someone ( L ) with no life at all but armed with all those mighty formulae ( conventions ? ) sits between them, picking teeth, and applying them to their dealings. B is a nice, old, honest B and sells goods exactly worth the money he gets. So far so good, the picking continues and the formulae rests. Then B gives S x amount of money to buy y kg of some good and the picking stops. Since B gave S x Rs, it could either be a ( - ) for B or a ( + ) for S considering that the good has not been exchanged yet. But the moment the good is exchanged, it is a ( + ) for B in terms of a good product ( and ofcourse ( - ) in terms of the money and hence considering only either one of the possibilities ) and a corresponding ( + ) for S in terms of the money he gained for the exchange. Thats the LHS. ( + ) and ( + ). The RHS or the outcome of the dealing would be a satisfied B for the good ( + ? ) and a satisfied S for the business he got ( + ? ) and hence a ( + ) eitherways on the RHS.
Very simple, straightwforward and non-revolting. So damn far and still so good.
So now, L , the guy with no life at all decides to try something which he then didn't realize would drive revolt up his ass. He very simply goes to S and buys a product which comes with a free something, F. S, honest and ambitious as he is, sells F alongwith the product with a logical expectation that the outcome of the dealing would be a ( + ) even if that amounts to a ( - ) in the actual dealing which is in the LHS. For L, the LHS is an obvious ( + ) and so is the outcome or the RHS. This means that when the LHS is a certain ( + ) * ( - ), the RHS can be ( - ) but according to business logic, it has a high possibility of being ( + ) too. Which then disproves MF2 atleast in one microcase and blows off L because he had read somewhere ( Zen and the art of Motorcycle Maintenance ? ) that even if a formula stands in a million cases but fails in just one, it is a failed formula.
Ok, so I am L and I'm of course wrong. What I'd love is an argument good enough to disprove the disproved and re-prove the original convention.

Talking about conventions, conventions of orthography says that a curved anything would appear as a straight line in the front view. Does that apply for a person with a squint?