content: {-
  
  values:
  eq :: (Bool, Bool) -> Bool
  le :: (Bool, Bool) -> Bool
  ne :: (Bool, Bool) -> Bool
  neg :: Bool -> Bool
  vee :: (Bool, Bool) -> Bool
  wedge :: (Bool, Bool) -> Bool
  
  scope:
  Prelude.eq |-> Prelude.eq, Value
  Prelude.le |-> Prelude.le, Value
  Prelude.ne |-> Prelude.ne, Value
  Prelude.neg |-> Prelude.neg, Value
  Prelude.vee |-> Prelude.vee, Value
  Prelude.wedge |-> Prelude.wedge, Value
  eq |-> Prelude.eq, Value
  le |-> Prelude.le, Value
  ne |-> Prelude.ne, Value
  neg |-> Prelude.neg, Value
  vee |-> Prelude.vee, Value
  wedge |-> Prelude.wedge, Value
  -}
  module Dummy where
  eq :: (Bool, Bool) -> Bool
  le :: (Bool, Bool) -> Bool
  ne :: (Bool, Bool) -> Bool
  neg :: Bool -> Bool
  vee :: (Bool, Bool) -> Bool
  wedge :: (Bool, Bool) -> Bool
  neg x
      =   case x of
              False -> True
              True -> False
  wedge (x, y)
      =   case (x, y) of
              (False, False) -> False
              (True, False) -> False
              (False, True) -> False
              (True, True) -> True
  vee (x, y) = neg (wedge (neg x, neg y))
  le (x, y) = vee (neg x, y)
  eq (x, y) = wedge (le (x, y), le (y, x))
  ne (x, y) = wedge (vee (x, y), neg (wedge (x, y)))
  