[Therion] The context of sd

[Andrew Atkinson]

Hello

It would appear that sd works within the centreline/endcentreline part
but not as part of a survey, however would it not be better if this
worked within the survey context.

Eg I have a few sump surveys with some dry surveys, all the sumps are
grouped into a single higher level survey for convenience

survey sumps

<===== It would be good to put the sd in here, rather than having to
specify it in
<===== every file, which is tedious when I decide to change it

include sump1.th
include sump1a.th
include sump2.th
....
include sumpn.th

equate # #
etc

endsurvey

This would be also useful when areas of the cave have been surveyed to a
lower grade.

just a thought

Andrew