Digital Logic Circuits Equivalence

Are the two circuits equivalent? explain your answer…

Answer

For the first circuit

(A or B) or C = A or B or C

because all or operators have the same precedence

For the second circuit

not (A and B and C) = (not A) or (not B) or (not C) (see de Morgan laws)

(http://en.wikipedia.org/wiki/De_Morgan%27s_laws)

The two circuits are not equivalent. This can also bee seen by writing the truth table for each circuit.