Corse title:
1.
Using Boolean algebra laws, a negation is denoted by a NOT gate in the circuit. Assume the input signal at X is 1. As it passes the NOT gate it becomes 0. Using Boolean algebra, note that NOT gate is a negation of the input signal, which is 1, hence the output becomes 0. This 0 is the input of the OR gate. This similar to the Y but, at Z the signal is not affected since there is no negation by NOT gate. The truth table for OR is a mathematical representation of Boolean algebra on logics is similar to above only that for TRUE and FALSE are represented by 1 and 0 respectively in the digital logic circuits.
2.
Using Boolean algebra laws, a negation is denoted by a NOT gate in the circuit. Consider an input signal at Z being 0. After passing the NOT gate, the output signal becomes 1. Using Boolean algebra, observe that NEGATION is denoted by the NOT gate such that, if input signal is 1 the output becomes 0 after passing via the NOT gate. This could be represented as TRUE or FALSE in terms of 1 or 0 respectively. The truth table for OR is a mathematical representation of Boolean algebra on logics is similar to above only that for TRUE and FALSE are represented by 1 and 0 respectively in the digital logic circuits.
3.
References
All about circuits (2011). All about circuits online textbook volume IV - Digital. Retrieved 2 May 2013 from http://www.allaboutcircuits.com/vol_4/index.html
Ohlsson, S. (2007) How a computer works - How it performs addition. Retrieved 2 may 2013 from http://home.swipnet.se/~w-24488/addition.html
Tala, D. (2011). Digital systems tutorial. Retrieved 2 May2013 from http://www.asic-world.com/digital/tutorial.html
Warren-Smith, D. (2006) Boolean Algebra Revisited. Retrieved 2 May2013 from http://users.senet.com.au/~dwsmith/boolean.html
