Are the parties any better off before or after the exhange?
There was a difference before and after the exchange, we will recognize all losses, regognize all gains
If there is no commercial substance we will recognize the losses but defer the gains
If "cash flows change after exchange", then there is commercial substance, recognize all gains and losses
if no commercial substance defer all gains unless party has a gain and recieved cash "boot" - recognize the gain that comes from cash, unless cash >= 25% of transaction, recognize all gains