Hi, I've defined the datatype:
data Graph a b = Empty | Context a b :& Graph a b
and the function
isEmpty :: Graph a b -> Bool
isEmpty Empty = True
isEmpty _ = False
and when I do a test run with the graph,
( [ ],2,'c',[("down",3)]) :& Empty
Haskell is bringing the message " Not in scope: data constructor `:&' "
Why is that so?
Kind regards
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