grhythm question

Hi, I'm new to PWGL so please excuse me if this is a kind of a newbie question.  I am using grhythm with pwgl-enum and pwgl-map.  The result is list of grtms, which separates into separate voices in the score-editor.  Is there an easy way to combine these separate lists into one grtm, which would show up as one long rhythm in one voice?  For example, I am getting a result like this:

 (((1/4 1/4 1/4 1/2 1/2 1/2 1/4 1/4 1/2) 0 100 100 100 100 100 100 100 100) ((1/2 1/2 1/4 1/4 1/2 1/2 1/4 1/2 1/4) 0 100 100 100 100 100 100 100 100) ((1/4 1/2 1/4 1/4 1/2 1/2 1/4 1/4 1/2) 0 100 100 100 100 100 100 100 100))

and I would like it to look like this (combined into one grtm):

 ((1/4 1/4 1/4 1/2 1/2 1/2 1/4 1/4 1/2 1/2 1/2 1/4 1/4 1/2 1/2 1/4 1/2 1/4 1/4 1/2 1/4 1/4 1/2 1/2 1/4 1/4 1/2) 0 100 100 100 100 100 100 100 100 0 100 100 100 100 100 100 100 100 0 100 100 100 100 100 100 100 100)

Thanks, in advance, for any advice.

Best,
Matt