Board
size
data Pos
posToPair
pairToPos
posToStr
strToPos
data Orient
orientToStr
strToOrient
data Placing
empty
isComplete
data PlaceResult a
place
data Complete
placingToComplete
data Membership
placingToMatrix
completeToMatrix
data LSR
data LC
data LB
sub
update
data LBC
completeToLBC
lbcToLB