sed question

[Susan Maxwell]

Got a sed question for you:  I'm creating a sed filter to mask out and
delete unwanted characters in a trace file.  I'm having trouble with this
configuration:

        LINE I:    PROMPT>
        LINE I+1:  >
        LINE I+2:  <

Whenever I see this series, I want to delete ALL THREE lines.  I can't
create a pattern /PROMPT\>\\n\>\\n\</d   as far as I can tell, because
sed won't allow patterns to span lines.  Is there a way to do this, without
resorting to awk or ed?   

Susan Maxwell