Question about Absorption Laws in Boolean Algebra

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Homework Help Overview

The discussion revolves around the absorption laws in Boolean algebra, specifically examining the definitions and properties associated with these laws. Participants are exploring the relationship between Boolean expressions and set theory interpretations.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the standard absorption laws and question the validity and terminology of a proposed "partial absorption" property. There is also an exploration of how these concepts relate to set theory, with references to Venn diagrams for clarification.

Discussion Status

The conversation is ongoing, with participants sharing their interpretations and seeking clarification on terminology. Some have provided insights into the relationship between Boolean algebra and set theory, while others are questioning the properties and their names without reaching a consensus.

Contextual Notes

Some participants express a lack of formal study in Boolean algebra, relying instead on set theory concepts. There is mention of a reference link to Wikipedia for further information.

polyglot
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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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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##.
 
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 :
$$A \cup C = A, A \cap D = A$$
 
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
 
Last edited by a moderator:
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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