categories: abcd=cba

[James Stasheff <jds@math.unc.edu>]

The pentagon relation abc=de
occurs all over the place.
I've just come across 

abcd = cba

for the first time.

Look familiar?

.oooO   Jim Stasheff		jds@math.unc.edu
(UNC)   Math-UNC		(919)-962-9607
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