The following diagram shows that 31 \(\not \Rightarrow\) 215 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 420 \( \not \Rightarrow \) 215 is not just a code 6 non-implication, but is also a code 4 non-implication.

215 This form is negation transferable
\(\Downarrow\)
83
\(\Downarrow\)
23 \( \not \Rightarrow \) 64
\( \Downarrow \)
27
\( \Downarrow \)
This form is transferable 31
\( \Downarrow \)
419
\( \Downarrow \)
420

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