{-@ unsafeIndexFQ :: x:Word16 -> a:Array -> o:Int -> l:Int -> i:Int
                  -> {v:Bool | ((Prop v) <=> (if (BtwnI x 55296 56319)
                                              then (SpanChar 2 a o l i)
                                              else (SpanChar 1 a o l i)))}
  @-}
unsafeIndexFQ :: Word16 -> Array -> Int -> Int -> Int -> Bool
unsafeIndexFQ = undefined
unsafeIndexFQ :: Word16 -> Array -> Int -> Int -> Int -> Bool
unsafeIndexFQ = undefined
unsafeIndexFQ = undefined