-functiontest :: TFVec D4 (Bit, Bit) -> (TFVec D4 Bit, TFVec D4 Bit)
-functiontest = \v -> let r = unzip v in r
+functiontest :: TFVec D4 (TFVec D3 Bit) -> (TFVec D12 Bit, TFVec D3 Bit, TFVec D3 (TFVec D3 Bit))
+functiontest = \v -> let r = (concat v, head v, tail v) in r