gf-3.2: examples/nqueens/NQueensAscii.gf
concrete NQueensAscii of NQueens = NatAscii ** {
lincat S, Matrix, Vec = Str ;
ListNat, Sat = {} ;
lin nqueens _ m = m ;
lin nilV _ _ = "" ;
consV _ j k _ _ v = j ++ "X" ++ k ++ ";" ++ v ;
matrix _ v = v ;
}