Chapter 8.3 - Minor correction

[sevanspowell]

I may be incorrect on this, but I think:

Here is another example of do notation, this type applied to the type constructor Maybe. Suppose we have some type XML representing XML nodes, and a function
child :: XML -> String -> Maybe XML

should read:

Here is another example of do notation, this time applied to the type constructor Maybe. Suppose we have some type XML representing XML nodes, and a function
child :: XML -> String -> Maybe XML