+.Pa mandoc.h
+and
+.Vt struct roff_man
+from
+.Pa roff.h
+as opaque types for function prototypes.
+.It Qq Pa roff_int.h
+Requires
+.Qq Pa roff.h
+for
+.Vt enum roff_type .
+.Pp
+Provides functions named
+.Fn roff_*
+to handle roff nodes and the two special functions
+.Fn man_breakscope
+and
+.Fn mdoc_argv_free
+because the latter two are needed by
+.Qq Pa roff.c .
+.Pp
+Uses the types
+.Vt struct eqn
+and
+.Vt struct tbl_span
+from