What is the definition of the following predetermined functions of the System.Random ::
to) randomRIO :: (Int,Int)-> IO Int
b) putChar :: Char -> IO ()
2
putChar is not defined along with randomRIO, but in System.IO. You can see the definition of both in Hackage. randomRIO: http://hackage.haskell.org/package/random-1.1/docs/System-Random.html#v:randomRIO. putChar: http://hackage.haskell.org/package/base-4.10.1.0/docs/System-IO.html#v:putChar.
putCharis not defined along withrandomRIO, but inSystem.IO. You can see the definition of both in Hackage.randomRIO: http://hackage.haskell.org/package/random-1.1/docs/System-Random.html#v:randomRIO.putChar: http://hackage.haskell.org/package/base-4.10.1.0/docs/System-IO.html#v:putChar.– luispauloml