how are terms modelled using my implementation eg1 : -a+a looks like T+(T-(Va), Va)

eg2 : (--a+-a)+a looks like T+(T+(T-(T-(Va)), T-(Va)), Va)

eg3: (x+y)+z expression 3 T+(T+(Vx, Vy), Vz)

eg4:x+(y+z) expression 4 T+(Vx, T+(Vy, Vz))

Complexity of expression 3: 2

Complexity of expression 4: 1

Expression 4 is simpler.