Decode this bug

[Daniel Wang]

So.. right now, I'm trying to use MLton as a backend. I generate a 
Cps.Program.t using Cps.DirectExp and then feed it to the rest of the
system, however when I run the Cps.typechek I get the exception

Bug: reference to Cons741 not in scope

uncaught exception Bug

Here's the printed version of the Cps code. It looks like Cons741 is "in
scope" I'm not sure what to make of it... (this is the only reference to
Cons741 in the program...)



Datatypes:
lst4 = Cons7 of [(int * lst4)]
       Nil6


Globals:


Functions:
fun copy_lst38(lst440: lst4): (lst4) = 
   let fun L_0(x_0: lst4@Cons7) = 
	   let val Cons741: (int * lst4) = Cons7#1 x_0
	       val t42: (int * lst4) = Cons741
	       val t58: int = #2 t42
	       val t59: lst4 = #3 t42
	       val x_1: lst4 = x_1
	       val t60: lst4 = #2 x_1
	       val t61: (int * lst4) = (t58, t60)
	       val t62: lst4 = Cons7(t61)
	   in Return (t62)
	   end
       fun L_1(x_2: lst4@Nil6) = 
	   let val t57: lst4 = Nil6()
	   in Return (t57)
	   end
   in case lst440 of
	Cons7 => L_0 | Nil6 => L_1
   end