Syntax of double brackets double quotes in excel -

I do not understand the syntax of the following rational test in the if statement in excel:

(Cell Designer "If the value is true, then the value is wrong." Can anyone explain what the brackets and quotes are checking?

In Valid values / string . It is about = IF (LN (A1) = 0 ... .

' in A1 .input = A1 < and TRUE will return.

Now = ISBLANK (A1) Try it, and it will come back to incorrect . Therefore, why did I use the valid

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