Page 29 - Nutshell 2

L was enjoying the opportunity to meet letters usually distant in some
other part of a word. After bumping into J, L observed that they, too,
had something in common.
“I never realized before,” said L, “that M and W looked like each other
upside-down; A and V almost do, too. But now I see that you and I are
mirror-images! The only difference is that your bottom is round and
mine is square.”
J looked at L carefully from both sides and had to agree. “Hey, S and
Z!” J yelled. “You’ve got the same relationship to each other that I have
with L: take a good look at yourselves.”
S and Z did just that; and, sure enough, they were like twins: one
curved, the other angular