copilot-verifier-demo: Fix warnings in Demo2

copilot-verifier-demo/src/Demo2.hs

@@ -24,11 +24,15 @@ temp = extern "temperature"
 ctemp :: Stream Float
 ctemp = (unsafeCast temp * constant (150.0/255.0)) - constant 50.0
 
+-- width of the sliding window
+window :: Int
+window = 5
+
 -- Compute the sliding average of the last 5 temps
 -- (Here, 19.5 is the average of 18.0 and 21.0, the two temperature extremes
 -- that we check for in the spec.)
 avgTemp :: Stream Float
-avgTemp = (sum 5 (replicate 5 19.5 ++ ctemp)) / fromIntegral 5
+avgTemp = (sum 5 (replicate 5 19.5 ++ ctemp)) / fromIntegral window
 
 spec :: Spec
 spec = do