User blog comment:Antares.I.G.Harrison/Complete Graham Notation/@comment-10429372-20150307073923

Wait a sec.

4. [a,b,c,d] = a^^^^...(a^^^^...(a^^^^...(a^^^^....^^^^b)...^^^b)...^^^b)...^^^^b where the first one has c arrows, the second one has a^^^...^^c (b arrows) arrows, and so on for d layers.

is not a valid expression, did you mean a{a{a{...{a{c}b}...}b}b}b with d a's?