The following diagram shows that 305 \(\not \Rightarrow\) 18 is a code 6 non-implication, and the theory of transferability then shows that it is actually a code 4. It follows that the non-implication 306 \( \not \Rightarrow \) 18 is not just a code 6 non-implication, but is also a code 4 non-implication.
| 67 | \( \not \Rightarrow \) | 18 | This form is negation transferable | |
| \( \Downarrow \) | ||||
| 89 | ||||
| \( \Downarrow \) | ||||
| 90 | ||||
| \( \Downarrow \) | ||||
| 91 | ||||
| \( \Downarrow \) | ||||
| This form is transferable | 305 | |||
| \( \Downarrow \) | ||||
| 306 |