{HEAD ~ This method} may include {TAIL ~ a ZMP calculating step} and a grounding position determining step 
include
{ HEAD ~ This method } may include { TAIL ~ a ZMP calculating step } and a grounding position determining step
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH