{HEAD ~ Boom} 16 has {TAIL ~ first and second arms} 20, 22 wherein second arm 22 is shorter than first arm 20 
has
{ HEAD ~ Boom } 16 has { TAIL ~ first and second arms } 20 , 22 wherein second arm 22 is shorter than first arm 20
HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH