The coupling of the roof to the floor, with a rigid member, allows for both deformation of both roof and floorpan while minimizing the decrease in {HEAD ~ distance} between the roof and {TAIL ~ floor} 
between
The coupling of the roof to the floor , with a rigid member , allows for both deformation of both roof and floorpan while minimizing the decrease in { HEAD ~ distance } between the roof and { TAIL ~ floor }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL