song 99 where song x = bott x 'N' , otw , ", " , bott x 'n' , '.' , NL , (x>0)-> ("Take one down and pass it around, ", bott (x-1) 'n' , otw , ".", NL , NL, song (x-1) ) ; ("Go to the store and buy some more, " , bott 99 'n' , otw , "." , NL ) and bott n opt= (((n=0)->(opt,"o more") ; n ), " bottle", ( (n=1)->();'s' ) , " of beer") and otw = " on the wall" ?