\dhead{gf}{sod-class-type @<class> @> @<c-type>}
\dhead{gf}{sod-class-chain-head @<class> @> @<class>}
\dhead{gf}{sod-class-chain @<class> @> @<list>}
\dhead{gf}{sod-class-type @<class> @> @<c-type>}
\dhead{gf}{sod-class-chain-head @<class> @> @<class>}
\dhead{gf}{sod-class-chain @<class> @> @<list>}