Hi,
I use Plplot v5.9.9
and
plmtex("b", 0, 1, 1, "#+S#+(#-freq#-)");
does not give overlines, underlines only all the Symbols are shown including #.
Other Sequences like unicode or subscript are working fine.
Output-device: png-cairo
If svg (not cairo) than the Escape-sequence is missing but no lines shown.
Thanks
Stefan