[Haskell-beginners] Problem specifying fst in tuple from list in filter

I can generate a tuple of (index,character) like this: zip [0..] ['A'..'Z'] To filter on an element in the list I can do: filter (== (0,'A')) $ zip [0..] ['A'..'Z']

[(0,'A')]

But that is very basic, I really want to select on index value (ie first item in pair). How do I specify the first part of tuple: filter (fst == 0) $ zip [0..] ['A'..'Z'] this doesn't work. Couldn't match expected type `(a1, Char) -> Bool' with actual type `Bool' In the first argument of `filter', namely `(fst == 0)' In the expression: filter (fst == 0) In the expression: filter (fst == 0) $ zip [0 .. ] ['A' .. 'Z']