Problem

Hi, I'm new to this board, so please don't flame me.

Anyway, I was having a discussion with somebody who claimed that 1 + 1 = 1. His example to prove it was thus:

"There are two stacks of paper on a table. If I put one stack on another stack, I'll still have one stack. Therefore, 1 + 1 = 1."

Same person here, why does this work?

Imprecise definition of "stack".  Sorta like saying one number + one number = one number.

He is misusing stack. He is using stacks interchangably with set; you can combine two sets, each with one item in the set, into one set with two items in the the set.

Stack = set
sheet = item in the set

the correct statement would be:

"I have two stacks of paper, each composed of one sheet. I combine the stacks, thus getting one stack with two sheets. 1+1=2"

I'm "he is misusing...", to simply get to the heart of the matter of what he is doing wrong:

He is going:

amount of sheet (1) + amount of sheet (1) = amount of sets (1)

units don't match, therefore the statement is invaild.

correct would be:

amount of sheet (1) + amount of sheet (1) = amount of sheets (2)

If he then tries and says "you can combine two sets and end up with one, thus 1+1=1". Reply that sets are not numbers and dont work that way.

That answered my question, thanks Anon.

http://en.wikipedia.org/wiki/Sorites_paradox