(({~(!A.&i.])@#)'BCFMS') [F..(128!:2"1 # ]) ];._2 (0 :0)
'B' ~: {:                NB. Baker not on top floor
'C' ~: {.                NB. Cooper not on bottom floor
'F' ~: {:                NB. Fletcher not on top floor
'F' ~: {.                NB. Fletcher not on bottom floor
</@i.&'CM'               NB. Miller on higher floor than Cooper
0 = +/@E.~&'SF'          NB. Smith not immediately below Fletcher
0 = +/@E.~&'FS'          NB. Fletcher not immediately below Smith
0 = +/@E.~&'CF'          NB. Cooper not immediately below Fletcher
0 = +/@E.~&'FC'          NB. Fletcher not immediately below Cooper
)