The attached document does not appear to be parsed
correctly by psgml, version 1.2.2. This can be seen by
showing the context in the second "b" element: psgml
returns "#PCDATA in B in B in A", whereas it should be
"#PCDATA in B in A". Indentation is wrong as well.
Oddly, describing "b" gives the correct result: that "b" is
excluded from its own content model.
P.S. psgml is the greatest thing on earth. I use it
constantly. Thank you so much.