A folding stairway interconnected with a basement window and its lock, for unlocking the window and opening the window when {HEAD ~ the stairs} are pivoted from a closed or folded position to {TAIL ~ a down, usable position} 
A folding stairway interconnected with a basement window and its lock , for unlocking the window and opening the window when { HEAD ~ the stairs } are pivoted from a closed or folded position to { TAIL ~ a down , usable position }
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 HEAD REL REL OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL