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Let’s Revisit


                    ♦ A proposition is a declarative statement that can either be true or false, but not both or any other value.
                    ♦ Well-formed formulas (WFF) is the representation of propositional logic in the form of symbols or abbreviations.
                    ♦ The left part (if) of a conditional is called an antecedent and the right part (then) is called a consequent.
                    ♦ Converse is the proposition obtained by interchanging the antecedent and consequent.

                    ♦ Inverse is the proposition obtained by taking the negated antecedent and the negated consequent in a conditional.
                    ♦ Contrapositive is the proposition that is inverse of its converse.
                    ♦ A tautology is a proposition that has 1 as its truth value, and a contradiction has 0 as its truth value.
                    ♦ A contingency has both 0 and 1 as its truth values.
                    ♦ A logic gate is a digital circuit that depicts a logical relationship between the input and output voltages of the circuit. They are
                   the building blocks of a digital circuit.
                    ♦ The AND gate produces 1 as output when all its inputs are 1.
                    ♦ The OR gate produces 1 as output when any one of its inputs is 1.
                    ♦ The NOT gate inverts the output.
                    ♦ The NAND and NOR gates are called universal gates as they can be used to implement operations of AND, OR and NOT
                   gates.
                    ♦ The XOR gate produces 1 for odd combinations of 1, and 0 in other cases.
                    ♦ The XNOR gate produces 0 for odd combinations of 1, and 1 for even combinations of 1 or all 0’s.
                    ♦ The half adder is a combinational circuit that is designed to perform the addition of two bits and produce the two binary
                   outputs as sum (S) and carry(C) bits.
                    ♦ The full adder is a combinational circuit that is designed to perform the addition of three bits and produce the two binary
                   outputs as sum (S) and carry(C) bits.








                                                              MIND DRILL



                   Solved Questions



              A.  Tick ( ) the correct option:
                  1.  Which of the following statements is a proposition?
                    a.  Get me a glass of water.
                    b.  May all your wishes come true!
                    c.  What is the value of π?
                    d.  The only odd prime number is 2.
                  2.  Let, P  : He is honest.
                        Q : He is dedicated.
                        R : He is hardworking. Then “He is honest or dedicated and not hardworking.”  is best represented by ………………… .
                    a.  ∼P V ∼Q V R                                 b.  P ∧ ∼Q ∧ R
                    c.  P V Q ∧ R                                   d.  P ∨ Q ∧ ∼R




                8888  Touchpad Computer Science-XI
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