julia> foldr((n, m) -> "($n + $m)", 0, 1:10)
"(1 + (2 + (3 + (4 + (5 + (6 + (7 + (8 + (9 + (10 + 0))))))))))"

julia> foldl((n, m) -> "($n + $m)", 0, reverse(1:10))
"((((((((((0 + 10) + 9) + 8) + 7) + 6) + 5) + 4) + 3) + 2) + 1)"