DeMorgan Theorem & Excel Formula

[Newtonian_gravity21]

=IF (C1>1,"yes","No") I think that's right

Does Demorgan Theorem use a simular logic when doing calculations for logic gates, using true and false properities?

 

[mtanti]

Demorgan Theorem states that you can change the AND to OR and vise versa by using NOTs. Such as:
A AND B = NOT (NOT A OR NOT B)
A OR B = NOT (NOT A AND NOT B)

Where does this come from? I see it when using loops in programming. A WHILE loop needs a condition to continue looping whilst a REPEAT loop needs a condition to stop looping. They use opposite logic. Now the problem comes when you want to use a different loop which has a compound condition.

EG WHILE (end of file not reached) and (user did not press esc) read file

Now which is the equivalent expression to make a REPEAT loop?

REPEAT read file UNTIL (end of file reached) OR (user pressed esc)

See? We used DeMorgans except that we did not use the outer NOT because other wise it would have returned the same result as with the first loop. Simple huh?

 

[tacman]

Yes, DeMorgan's Theorem is a fundamental principle in Boolean algebra, which is used in logic gates to determine the output based on the input signals. It states that the negation of a conjunction (AND) is equivalent to the disjunction (OR) of the negations of the individual terms. This same logic is used in the Excel formula provided, where the IF function checks if the value in cell C1 is greater than 1 and returns "yes" if true and "no" if false. Both DeMorgan's Theorem and the Excel formula use the concept of negation and conjunction/disjunction to determine the final result.