constructing a nand gate

talk about over complicating things...... could anyone possibly try to explain this in a more complicated method than has been done thus far?  why is it that it cannot be simply stated (the goal) like saying, "my car uses seperate turn signal and brake light bulbs, and i would like to consolidate all the signals into a single output circuit for each side, how do i do this?"  -- that was only an example, since i already know how to accomplish that circuit (and any other automotive circuit actually).... i'm just saying why not make it simple.  a nand gate logic looks like this:

and it works like this:

now, why you would want a light on when the input from both turn signals and brakes are zero is totally beyond me....  i'm guessing (because i have to due to the way your question was asked) that what you're really looking for is an XOR circuit ... which works like this:

either of those should be pretty easy to make from relays, but it helps to know for sure which / what you need first.

Hey chuckles if you read the first post you might notice where I state what I want to acheive, "I have a honda crx that uses two wires for the turn signals and two for the brake lights and I want to convert it to 2 wires so that the brake lights signal my turns".  If you already know how to solve my problem why have you not yet demonstrated it? even after the problem was already solved.

I know that I just need the input wire for the flasher, so problem solved.

thanks