
tcfail143.hs:29:9:
    Couldn't match type `S Z' with `Z'
    When using functional dependencies to combine
      MinMax a Z Z a,
        arising from the dependency `a b -> c d'
        in the instance declaration at tcfail143.hs:11:10
      MinMax (S Z) Z Z Z,
        arising from a use of `extend' at tcfail143.hs:29:9-16
    In the expression: n1 `extend` n0
    In an equation for `t2': t2 = n1 `extend` n0

tcfail143.hs:29:9:
    Couldn't match type `Z' with `S Z'
    When using functional dependencies to combine
      MinMax Z Z Z Z,
        arising from the dependency `b c d -> a'
        in the instance declaration at tcfail143.hs:10:10
      MinMax (S Z) Z Z Z,
        arising from a use of `extend' at tcfail143.hs:29:9-16
    In the expression: n1 `extend` n0
    In an equation for `t2': t2 = n1 `extend` n0
