Selected Answer
I have to admit that I don't know which "scheme 4" you refer to, nor can I imagine what an "IF box" might be - perhaps because I don't have a Mac. But I do know the IF statement in Excel which you can [LINK URL="Excel IF Statement – How to Use (exceltrick.com)]"learn here[/LINK]. (Sorry, I can't get this link to work as it should. Just Google for "Excel IF statement" and take any of the results.)
The OR statement consists of a series of conditions that returns TRUE if any of the expressions in it are true. For example,
=OR(2>3, 3=4, 4>3)
evaluates to
=OR(FALSE,FALSE,TRUE)
Therefore the overall result is TRUE.
You can build the OR statement into an IF statement in place of a simpler expression for evaluation.
=IF(OR(2>3, 3=4, 4>3),TRUE,FALSE)
This function will execute the TRUE part of the IF statement because the OR statement evaluates to TRUE.
By the way, the AND statement works exactly like the OR statement except in it all expressions must evaluate to TRUE, not just one.
UPDATE (in response to your file) =============================
This looks like a task from school. Therefore the answer I gave above is exactly what you should have.
Your syntax in D28 is correct. Therefore, if the result doesn't agree with your excpectations look at the logic of the expressions.
In a nested IF statement, the False result is replaced with another IF statement (this one nested into the first). So, the logic will be: IF the first condition is True, give one result, Else, if another condition is True, give another result, but if that second condition is False give a default result. That second False could again be an IF statement with a third condition - up to 7 deep.
The way to construct nested IFs is to construct each one in its own cell for testing and then copy/paste.
[one cell] =IF(D4>=D13,True,False)
[another cell] = IF(D9>=D14, True, False)
[Combined] =IF(D4>=D13,True,IF(D9>=D14, False, True))
The second IF statement took the place of the bold False in the first. That's how the double closing parentheses came about.