# copy (1) to (2) using (3)

+++++ # set (1) = 5

.>.< # show (1) and (2)

[->+>+<<] # set (3) = (2) = (1) and (1) = 0

.>.>. # show (1), (2) and (3)

[-<<+>>] # set (1) = (3) (initial) and (3) = 0

<< # got to (1)
.>.>. # show (1), (2) and (3)