Question about Absorption Laws in Boolean Algebra

In summary, the Absorption Laws in Boolean Algebra state that certain expressions can be simplified through specific identities. These laws include A + AB = A and A(A + B) = A, demonstrating how a variable can absorb other terms in a logical operation. Understanding these laws is crucial for simplifying Boolean expressions in digital logic design and circuit analysis.
  • #1
polyglot
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4
Homework Statement
Absorption laws in Bollean algebra
Relevant Equations
¬q ∧ (¬p∨q)
According to my notes, the absorption law states that p ∨ (p ∧ q) = p, p ∧ (p ∨ q) = p
I have found a video where they were discussing a partial absorption such as ¬q ∧ (¬p∨q) = ¬q ∧ ¬p
This is not in my notes, but is this correct? specifically, is the terminology used to decribe this property the correct one?
 
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  • #2
polyglot said:
Homework Statement: Absorption laws in Bollean algebra
Relevant Equations: ¬q ∧ (¬p∨q)

According to my notes, the absorption law states that p ∨ (p ∧ q) = p, p ∧ (p ∨ q) = p
I have found a video where they were discussing a partial absorption such as ¬q ∧ (¬p∨q) = ¬q ∧ ¬p
This is not in my notes, but is this correct? specifically, is the terminology used to decribe this property the correct one?
I've never studied boolean algebra, so I look at these in terms of set theory. The absorption laws are simply:
$$A \cup (A \cap B) = A, \ A \cap (A \cup B) = A$$Which are obvious from a Venn diagram.

In the partial absorption you quote, note that only ##\neg p## appears, so you might as well replace that with ##p##. In any case, straighteming out the logic and confusing order, this says:
$$A \cap (A' \cup B) = A \cap B$$Which is also obvious from a Venn diagram.

PS in this last one I took ##\neg q \leftrightarrow A## and ##\neg p \leftrightarrow B##. ##A'## is the complement of ##A##.
 
  • #3
PeroK said:
I've never studied boolean algebra, so I look at these in terms of set theory. The absorption laws are simply:
$$A \cup (A \cap B) = A, \ A \cap (A \cup B) = A$$
More generally, if ##C ## is any subset of ##A## and ##D## is any superset of ##A##, then :
$$A \cup C = A, A \cap D = A$$
 
  • #4
PeroK said:
I've never studied boolean algebra, so I look at these in terms of set theory. The absorption laws are simply:
$$A \cup (A \cap B) = A, \ A \cap (A \cup B) = A$$Which are obvious from a Venn diagram.

In the partial absorption you quote, note that only ##\neg p## appears, so you might as well replace that with ##p##. In any case, straighteming out the logic and confusing order, this says:
$$A \cap (A' \cup B) = A \cap B$$Which is also obvious from a Venn diagram.

PS in this last one I took ##\neg q \leftrightarrow A## and ##\neg p \leftrightarrow B##. ##A'## is the complement of ##A##
Thanks - it is useful to look at it using a Venn diagram.
Is there a name for this property then p ∨ ( ¬p ∧ q) = p ∨ q
 
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  • #5
polyglot said:
Thanks - it is useful to look at it using a Venn diagram.
Is there a name for this property then p ∨ ( ¬p ∧ q) = p ∨ q
It's not fundamental, as it is a consequence of the distribution of ##\vee## over ##\wedge##, complementation and identity laws.
 
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FAQ: Question about Absorption Laws in Boolean Algebra

What are the Absorption Laws in Boolean Algebra?

The Absorption Laws in Boolean Algebra are two identities that simplify expressions by "absorbing" terms into simpler forms. They are: A + (A * B) = A and A * (A + B) = A. These laws help reduce the complexity of Boolean expressions.

Why are Absorption Laws important in Boolean Algebra?

Absorption Laws are important because they simplify Boolean expressions, making it easier to design and analyze digital circuits. By reducing the number of terms and operations, these laws help optimize logic circuits for efficiency and performance.

Can you provide an example of using the Absorption Laws?

Sure! Consider the expression A + (A * B). According to the first Absorption Law, this simplifies to A. Similarly, for the expression A * (A + B), the second Absorption Law tells us that this also simplifies to A.

How do Absorption Laws relate to other Boolean Algebra laws?

Absorption Laws are part of a larger set of Boolean Algebra laws, including De Morgan's Laws, Distributive Laws, and Identity Laws. Together, these laws provide a comprehensive toolkit for manipulating and simplifying Boolean expressions, each addressing different aspects of expression transformation.

Are Absorption Laws applicable in practical digital circuit design?

Yes, Absorption Laws are highly applicable in practical digital circuit design. They help in minimizing the number of gates and connections needed, which can reduce cost, power consumption, and improve the overall performance of the circuit.

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