{HEAD ~ A proposition} is to provide {TAIL ~ a wearable display} suitable for enjoying contents including images by plural users simultaneously 
is to provide
{ HEAD ~ A proposition } is to provide { TAIL ~ a wearable display } suitable for enjoying contents including images by plural users simultaneously
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH