Hi, When testing this netwire sample program {-# LANGUAGE Arrows #-} import Control.Wire mainWire :: WireP () Double mainWire = proc i -> do rec value <- integral_ 0.0 -< oldValue oldValue <- delay 1.0 -< value returnA -< value main = do wireLoop mainWire wireLoop :: WireP () Double -> IO () wireLoop w' = do let (mx, w) = stepWireP w' 1.0 () case mx of Left ex -> putStrLn $ "Inhibited:" ++ (show ex) Right x -> putStrLn $ "Produced:" ++ (show x) wireLoop w I get this output: NetwireTest: <<loop>> But there should be not infinite loop, should there? Regards, Nathan