I've started learning about set theory and the book I'm using, in the first couple of paragraphs, isn't quite as detailed and rigorous as I would like it to be, so I'm left with quite some questions. A more advanced student of Mathematics has been able to answer most of them for me, but I'm still stuck with one problem, which is the statement that [tex](x, (y, z)) = ((x, y), z) = (x, y, z).[/tex] The parentheses denote ordered pairs (or a triplet, in the last case). Would anyone show me why this is true? Or is this too advanced to understand after ten pages of set theory?