[cyleigh]

I am trying to write a traversal algorithm for my OG document, and am having trouble with lines that do not have nodes on both ends (which is allowed in my document).

Script Debugger tells me that eg/ source is <>, but how do I reference that in my code? I want something like:

if (source of vertex is not equal to <>) then
  dft(source of vertex)
end if

but this doesn't compile, and "missing value" substituted for empty doesn't work either. What do I need to be writing?