Carey Brown wrote:What problems are you seeing? Are all of them wrong? Only some? Which ones? What output did you expect?
Just noticed you were using color to indicate bad output. I'm slightly color blind and couldn't see it. It is preferable to use bold, italic, or underline for this reason.
 +  = 0
 +  = 1
 + [x] = x
[3 x] + [-3 x] = 0 x