Cannot build Running heads using @Val

[Jeff Kingston]

  symbol @Val unknown or misspelt

Well, the message means it isn't in scope.  So if @Val exists at all,
it must either be defined after the point of invocation where Lout is
complaining, or else it must be local to some other symbol.  If local
to some other symbol, I guess the most likely intention is to get at
it by an @Open symbol, in which case the most likely reason why this
is not working is that @Val needs to be exported to be accessible by
@Open.

I wouldn't trust anything you read in "A New Approach to Document
Formatting."  It's very old, and it never claimed to get down to
the details.  This kind of thing is documented in the expert's
guide, "Document Formatting with Lout", and to create running headers
you need that manual.

Jeff.