doc-src/IsarRef/Thy/document/HOL_Specific.tex

 \rail@nont{\hyperlink{syntax.term}{\mbox{\isa{term}}}}[]
 \rail@nextplus{1}
 \rail@endplus
 \rail@end
 \rail@begin{2}{\isa{spec}}
-\rail@nont{\hyperlink{syntax.typespec}{\mbox{\isa{typespec}}}}[]
+\rail@nont{\hyperlink{syntax.typespec-sorts}{\mbox{\isa{typespec{\isaliteral{5F}{\isacharunderscore}}sorts}}}}[]
 \rail@bar
 \rail@nextbar{1}
 \rail@nont{\hyperlink{syntax.mixfix}{\mbox{\isa{mixfix}}}}[]
 \rail@endbar
 \rail@term{\isa{{\isaliteral{3D}{\isacharequal}}}}[]