(GOAL COMPLEXITY)
(STARTTERM CONSTRUCTORBASED)
(VAR @l @l1 @l2 @l3 @x @xs @y @ys @z @zs )
(STRATEGY INNERMOST)
(RULES 
        group3(@l) -> group3#1(@l)
        group3#1(::(@x, @xs)) -> group3#2(@xs, @x)
        group3#1(nil) -> nil
        group3#2(::(@y, @ys), @x) -> group3#3(@ys, @x, @y)
        group3#2(nil, @x) -> nil
        group3#3(::(@z, @zs), @x, @y) -> ::(tuple#3(@x, @y, @z), group3(@zs))
        group3#3(nil, @x, @y) -> nil
        zip3(@l1, @l2, @l3) -> zip3#1(@l1, @l2, @l3)
        zip3#1(::(@x, @xs), @l2, @l3) -> zip3#2(@l2, @l3, @x, @xs)
        zip3#1(nil, @l2, @l3) -> nil
        zip3#2(::(@y, @ys), @l3, @x, @xs) -> zip3#3(@l3, @x, @xs, @y, @ys)
        zip3#2(nil, @l3, @x, @xs) -> nil
        zip3#3(::(@z, @zs), @x, @xs, @y, @ys) -> ::(tuple#3(@x, @y, @z), zip3(@xs, @ys, @zs))
        zip3#3(nil, @x, @xs, @y, @ys) -> nil
        
)