T7609.hs:7:16: error:
• Expecting one more argument to ‘Maybe’
Expected a type, but ‘Maybe’ has kind ‘* -> *’
• In the type signature: f :: (a `X` a, Maybe)
T7609.hs:10:7: error:
• Expected a constraint, but ‘a `X` a’ has kind ‘*’
• In the type signature: g :: (a `X` a) => Maybe
T7609.hs:10:19: error:
• Expecting one more argument to ‘Maybe’
Expected a type, but ‘Maybe’ has kind ‘* -> *’
• In the type signature: g :: (a `X` a) => Maybe