I am reading the grammar book "Practical English Usage" by Michael Swan. In the book it stated when we are not talking about 'unreal' situations, we use the same tenses with if as with other conjunctions.
If you didn't study physics at school, you won't understand this book.
To the best of my knowledge, only type 3 can be used to talk about unreal situations. And in the quote above, it is probably type 1, which the tenses should be present tense and will + infinitive.
My question is: Why shouldn't I use would instead of will, given that would is the past form of will? I used to learn that the "result" part is in future tense. Is it that will a fixed formula which I have to use will regardless of the time I am referring to?