AtD translation: the thing about a Quaternion ‘is’ is that

[Mike Jing]

P538.38-539.3   “Cambridge personality Bertie (‘Mad Dog’) Russell
observed,” observed Barry Nebulay, “that most of Hegel’s arguments come
down to puns on the word ‘is.’ In that sense the thing about a Quaternion
‘is’ is that we’re obliged to encounter it in more than one guise.  As a
vector quotient. As a way of plotting complex numbers along three axes
instead of two. As a list of instructions for turning one vector into
another.”

So in this sentence, the word "Quaternion" is supposed to be a modifier for
the word " 'is' ", is that correct?