Boolean Algebra - Introduction to Logical Operators and Gates
Boolean algebra, or Boolean logic, is a mathematical system that analyses and manipulates logical statements. It is a fundamental tool used in digital electronics and computer science. It is also a branch of mathematics that deals with binary variables, i.e., variables that can only take on two values, usually represented as 0 or 1.
Furthermore, if we think, "what is Boolean algebra?" the additional answer would be that it deals with the algebraic operations of logic, such as the logical AND, OR, and NOT operations. Boolean algebra is an essential tool in computer science and digital electronics, as it forms the basis of digital circuits, software programs, and computer systems.
This blog will introduce the basics of Boolean algebra, including logical operators, gates, and truth tables. Also, we will be talking about the three laws of Boolean Algebra and Boolean Identities. So, let us begin!
Logical Operators
Logical operators are the building blocks of Boolean algebra. They are used to create analytical expressions, which evaluate either true or false. There are three primary logical operators in Boolean algebra:
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AND Operator: The AND operator returns true only if both inputs are valid. The symbols that denote it are ∧ or ⋅. For example, if A and B are two logical values, then A ∧ B is right only if both A and B are true.
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OR Operator: The OR operator returns true if either of its inputs is true. For example, if A and B are two logical values, A ∨ B is true; if A is true, B is true, or both A and B are true. The symbol ∨ or + denotes it.
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NOT Operator: The NOT operator is a unary operator that returns the opposite of its input. The symbol ¬ or ~ denotes it. For example, if A is a logical value, then ¬A is true if A is false, and false if A is true.
Gates
Boolean algebra uses logic gates to implement logical operations. A logic gate is an electronic component which performs a Boolean algebraic function on one or more input signals and produces a single output signal. The three primary logic gates are:
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AND Gate: The AND gate has two or more inputs and one output. It returns true only if all its inputs are true. The symbol denotes the AND gate ∧.
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OR Gate: The OR gate has two or more inputs and one output. It returns true if any of its inputs are true. The symbol denotes the OR gate ∨.
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NOT Gate: The NOT gate has one input and one output. It returns the opposite of its information. The NOT gate's symbol is ¬.
Truth Tables
A truth table shows the output of a logical expression for all combinations of input values. Truth tables test analytical expressions' correctness and design logic circuits.
Let's take the example of an AND gate with inputs A and B. The truth table for this gate is:
In the above table, A and B are the input values, and A ∧ B is the output value. The truth table shows that the AND gate returns a false output unless both inputs are accurate.
Similarly, the truth table for an OR gate with two inputs, A and B, is:
NAND Gate
The NAND gate is universal, i.e. you can use it to construct any other logic gate. It is also called a "not and" gate because it negates an AND gate. The output of a NAND gate is low (0) only when all of its inputs are high (1), otherwise, the result is high (1).
The symbol of a NAND gate is similar to that of an AND gate but with a small bubble on the output line.
What are the three laws of Boolean algebra?
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The first law is the commutative law, which states that the order of operands in a Boolean expression does not matter. In other words, the expression A + B is equivalent to B + A, and the expression A * B is equivalent to B * A.
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The second law is the associative law, which states that grouping operands in a Boolean expression does not matter. In other words, the expression (A + B) + C is equivalent to A + (B + C), and the expression (A * B) * C is equivalent to A * (B * C).
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The third law is the distributive law, which states that the distribution of operands in a Boolean expression over addition or multiplication is valid. In other words, the expression A * (B + C) is equivalent to (A * B) + (A * C), and the expression A + (B * C) is equivalent to (A + B) * (A + C).
These three laws are essential in simplifying and manipulating Boolean expressions to analyze and design digital circuits.
What are Boolean identities?
Boolean identities are a set of laws in 'what is Boolean algebra' that help simplify complex Boolean expressions by expressing them in simpler forms. These identities follow from the three fundamental laws of Boolean algebra: commutative, associative, and distributive laws. You can use the Boolean identities to verify the correctness of Boolean expressions, simplify complex words, and derive new expressions.
1. Complement law: This law states that the complement of a Boolean variable is its negation. When we complete an input variable, its value is flipped from 0 to 1 or vice versa, and you can use the expressions. A + A' = 1 and A * A' = 0
2. Identity law states that the identity element for addition and multiplication is 0 and 1, respectively. These values don't change the result of the operation and can be used to simplify expressions by replacing a term with its identity element. A + 0 = A and A * 1 = A
3. Double negation law states that a variable equals its double negation. This can be useful in simplifying expressions by eliminating double negations. A = (A').'
4. De Morgan's law: These laws state that the complement of a disjunction (OR) is the conjunction (AND) of the complements of the terms, and the complement of a conjunction (AND) is the disjunction (OR) of the complements of the terms. You can use these laws to simplify complex expressions involving multiple variables. A' * B' and (A * B)' = A' + B'
5. Absorption law: These laws state that you can simplify the variables combined with a term it already appears within an AND operation or in an OR operation can be simplified. These laws can reduce the number of terms in an expression and simplify Boolean algebraic expressions. A and A * (A + B) = A
Conclusion
Now you know what Boolean Algebra is? A good understanding of Boolean algebra is essential for anyone interested in digital circuit design or computer science. Cuemath's online math classes offer a comprehensive learning experience for students of all ages interested in learning about Boolean algebra, digital circuits, and computer science. With expert teachers and personalized lesson plans, Cuemath can help you master complex concepts and take the first step towards a successful career in technology.