Wrong argument order in abstract refinement for dependent tuples

[pacastega]

This program:

{-@ lists :: (l::Int, {vv:[Int] | len vv = l}, {vvv:[Int] | len vvv = l}) @-}
lists :: (Int, [Int], [Int])
lists = (3, [1, 2, 3], [7, 8, 9])

results in the following error:

    Sort Error in Refinement: {vvv : [int] | len vvv == l}
    The sort [int] is not numeric
  because
Cannot unify int with [int] in expression: len vvv == l 
  because
Invalid Relation len vvv == l with operand types int and [int]

The problem persists when writing the dependent pair explicitly using an abstract refinement,

{-@ lists :: (Int, [Int], [Int])<\n -> {vv:[Int] | len vv = n}, \n _ -> {vvv:[Int] | len vvv = n} > @-}

but goes away when swapping the order of the arguments of the last lambda (n and _):

{-@ lists :: (Int, [Int], [Int])<\n -> {vv:[Int] | len vv = n}, \_ n -> {vvv:[Int] | len vvv = n} > @-}