There isn't any "application f e".
Any human reader who does that is simply WRONG to do so.

Sorry, should have written f*

In your fragmentary example, <monster computation> may be discarded
EVEN IF it contains IO expressions, it's only if they are linked into
the IO chain using >> and/or >>= that the environment will perform
their values.

Thanks. I see the error of my ways. So, IO expressions must be evaluated if they are in the chain leading to main.

-gregg