Naming Output Signals

Suppose you have a block diagram bd that outputs two signals, and you would like to give them names. You cannot simply say ``x,y = bd'' as you would in matlab. Instead, use the signal blocking operator `!':

  x = bd : _,!;
  y = bd : !,_;

This does not result in two instances of bd. The optimization recognizes the common subexpression bd and computes it only once.