(ㅌㅅㅌ)

  fun bruijn(le, lamlist) =
	let fun depth(s, lst) = if lst=[] then raise NotClosed
  			   else if List.hd(lst)=s then 0
  			   else 1+depth(s,List.tl(lst))
  	in
  	  case le of VAR(s) => I(depth(s, lamlist))
  	  	   | LAM(s, e) => L(bruijn(e, s::lamlist))
  	  	   | APP(e1, e2) => A(bruijn(e1,lamlist), bruijn(e2,lamlist))
  	end
  
  fun bruijnize le = bruijn(le, []) 

:roll: :D :shock: :) :o :lol: