[TUHS] GNU eqn clarifications and reforms

[Douglas McIlroy]

I am not convinced that using special characters rather than in-line
eqn is a good thing. It means learning a whole new vocabulary.  Quick,
what's the special character for Greek psi?

I have found that, for a sequence of displayed equations as in an
algebraic derivation, a pile often looks more coherent than a sequence
of EQ-EN pairs. The pile can even contain interleaved comments, as in
Hoare-style proofs.

Doug