% This is a cut-down version of the program that causes the following
% assertion failure in the compiler:
% 
% Software Error: jumpopt.m: Unexpected: adjust_livevals:
% 	BetweenLivevals and PrevLivevals differ
%
% (This is bug #6 in mantis.)
%
% To reproduce the bug compile with, -0 --optimize-frames --optimize-repeat=2
% in grade {asm_fast,reg,none}.gc.

:- module endo2.
:- interface.

:- import_module list.
:- import_module io.

:- type tree
    --->    l
    ;       br(tree, tree).

:- pred write_dnas(list(list(tree))::in, io::di, io::uo) is det.

:- implementation.

write_dnas(D0, !IO) :-
    ( dna_head_tail(D0, D) ->
        write_dnas(D, !IO)
    ;   	 
       	true 
    ).

:- pred dna_head_tail(list(list(tree))::in, list(list(tree))::out)
	is semidet.

dna_head_tail([[] | Fs0], Fs) :-
    dna_head_tail(Fs0, Fs).