Another difficult 条件文

We talked about conditional sentences a while ago.

• conditional sentence - 条件文

Here's a link to the last post in the series, for review:

http://upgradeenglish.blogspot.com/2009/06/if-you-are-sure-something-will-happen.html

Here's a more advanced conditional sentence which doesn't seem to follow the rules we talked about before. First though, we talked about this simple conditional sentence before:

If __(condition), __(main clause, result)__.
If it rains, we'll get wet. <- the condition is "it rains", and the result is "we'll get wet"

Here's more about first conditional sentences:
http://upgradeenglish.blogspot.com/2009/06/if-i-dont-hang-this-laundry-tonight-it.html

If __(s)__ __(be+v+infinitive)__, __(main clause)__.
(desired situation) , (prerequisite)
前提条件 (ぜんていじょうけん) (n) precondition; prerequisite; (definition from Edict)
If we are to stay dry, we have to take our umbrellas. <- Taking our umbrellas is necessary for staying dry. If we are going to stay dry, we have to take our umbrellas. (also OK)

This looks like future in the "if" clause. However, in this case, "are to stay dry" or "are going to stay dry" basically means "want to stay dry". So, you could say this:

If we want to stay dry, we have to take our umbrellas.

There... it looks like a regular first conditional sentence.

I was early to class on Thursday. The classroom is on the 14th floor of a building at Shiba-Koen, and I was enjoying the view of Shiodome. Then I thought to myself, "if I am to have a smooth class, I had better start to prepare for the lesson." Before I did that, though, I took this picture.

There's still a lot to be done tonight. If I am to sleep before 3am, I should finish this post and get on to the next task. Enjoy your weekend!