Sequence of tenses (#4)

[gorikaz]

Could anybody please help me understand why the following underlined parts are kept as a present tense, not a past tense? In my understanding, if they are followed by the rules of the "sequence of tenses," they should be a past tense, no??

Example 1: It would be unforgivable if this turns out to be true.
Example 2: He told the directors he would sue them if the company takes anti-takeover measures.
Example 3: She said that she would not run if that political party fields its own candidate.

If the above underlined parts were changed to the past tense, how would they sound?

[rewboss]

The "sequence of tenses" is not very useful, I'm afraid.

In each case, the present tense indicates that the condition is very possible. It is possible that "this" in example 1 will turn out true; it is possible that the company will take anti-takeover measures; and it is possible that the political party will field its own candidate.

In if-clauses, we use the past tense to indicate that a condition is highly improbable, impossible or unreal:

If the moon was made of cheese... (but it's not made of cheese)

If pigs could fly... (but pigs can't fly)

If I lived in Australia... (but I live in Germany)

[gorikaz]

I see, so does it mean that these three sentences are gramatically correct just as written (= underlined parts with the present tense)? Do you mean that I should change these underlined parts only if these "if-clauses" indicate the condition which is highly improbable, impossible, or unreal? Is my understanding correct?

By the way, does this principle apply to formal writing as well?