- \ifcase\ifx\next\hbox\tw@\fi
- \ifx\next\vbox\tw@\fi
- \ifx\next\vtop\tw@\fi
- \ifx\next\box\@ne\fi
- \ifx\next\copy\@ne\fi
- \ifx\next\vsplit\@ne\fi
- \ifx\next\lastbox\@ne\fi
+ \ifcase\ifx\ltj@@next\hbox\tw@\fi
+ \ifx\ltj@@next\vbox\tw@\fi
+ \ifx\ltj@@next\vtop\tw@\fi
+ \ifx\ltj@@next\box\@ne\fi
+ \ifx\ltj@@next\copy\@ne\fi
+ \ifx\ltj@@next\vsplit\@ne\fi
+ \ifx\ltj@@next\lastbox\@ne\fi