Should fold underlines onto blanks even with the ‘
-' option so that a true underline character would show.
Can't back up more than 102 lines.
General overstriking is lost; as a special case ‘|' overstruck with ‘-' or underline becomes ‘+'.
Lines are trimmed to 132 characters.
Some provision should be made for processing superscripts and subscripts in documents which are already double-spaced.