Evaluate NOT()

Context

Assuming 0 is false and any other value is true, NOT can be evaluated using a mechanism similar to if / then / else : if true, then reset result; set result to 1 otherwise. This can be implemented using a mechanism similar to if / then / else.

Initial state

• Memory: A, 0
• Cursor: first cell
• Input: any

Process

• Set second cell to 1
• While first cell is not null
• Reset first cell
• Reset second cell
• Copy second cell to first one
• Go back to first cell (optional)

Code 

>+<[[-]>-<]>[-<+>]<

Final state

• Memory: not(A), 0
• Cursor: first cell
• Input: any
• Output: unchanged