% line 6 testex.mp TeX \hsize="a0 inmore TeX % with comments% \shipout\hbox{\smash{\hbox{\hbox{% line 10 testex.mp $a+b$}\vrule width1sp}}} \shipout\hbox{\smash{\hbox{\hbox{% line 10 testex.mp An initial newline is now ignored.}\vrule width1sp}}} \end{document}