Simplifying Boolean expressions

  • #1
polyglot
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4
Homework Statement
I need to simplify the following expression if at all possible and explain the steps
Relevant Equations
[(p∨t)∧r]∨[(p∨t)∧¬r]
This is the first time I am doing logic so the question is probably stupid, but could I just factorise (p∨t)∧[(r v¬r] or perhaps you cannot do that in Boolean algebra?
 
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  • #2
polyglot said:
Homework Statement: I need to simplify the following expression if at all possible and explain the steps
Relevant Equations: [(p∨t)∧r]∨[(p∨t)∧¬r]

This is the first time I am doing logic so the question is probably stupid, but could I just factorise (p∨t)∧[(r v¬r] or perhaps you cannot do that in Boolean algebra?
:welcome:
I'm not sure "factorise" is the correct term. What axioms or theorems do you have at your disposal? The deMorgan laws?
 
  • #3
deMorgan laws, distributive, absorption law etc. I am assuming the usual ones...?
 
  • #4
polyglot said:
deMorgan laws, distributive, absorption law etc. I am assuming the usual ones...?
If you replace ##p \vee t## by ##q## can you see anything to do?
 
  • #5
If I cannot 'factorise', then I was going to use distributive but not sure how to apply it and then continue with the simplification?
 
  • #6
polyglot said:
If I cannot 'factorise', then I was going to use distributive but not sure how to apply it and then continue with the simplification?
Show us what you are thinking. Here's some Latex to help (*):
$$\big[(p \vee t) \wedge r \big ] \vee \big [(p∨t)∧\neg r \big ]$$Is factorise a thing in your course notes? Maybe it's terminology I'm not familiar with in this context.

(*) if you reply to my post you can copy and paste the Latex.
 
  • #7
I am thinking if the distributive property states that p ∧ ( q ∨ r) = ( p ∧ q) ∨ ( p ∧ r) surely in my original question I just need to apply it in reverse and obtain (p∨t)∧[(r v¬r] . I think this is distributive - factorising does not appear on my notes. Is this correct?
 
  • #8
polyglot said:
I am thinking if the distributive property states that p ∧ ( q ∨ r) = ( p ∧ q) ∨ ( p ∧ r) surely in my original question I just need to apply it in reverse and obtain (p∨t)∧[(r v¬r] . I think this is distributive - factorising does not appear on my notes. Is this correct?
That looks like a good first step.
 
  • #9
Then, I think I know how to go on: r v¬r is always True, and therefore I will end up with p∨t. Does it look OK to you?
 
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  • #10
polyglot said:
Then, I think I know how to go on: r v¬r is always True, and therefore I will end up with p∨t. Does it look OK to you?
Yes. The point of studying boolean algebra is to make the obvious difficult, isn't it? Only joking!
 
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  • #11
You are aboslutly right! Thanks for your help!
 
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FAQ: Simplifying Boolean expressions

What is the purpose of simplifying Boolean expressions?

Simplifying Boolean expressions aims to reduce the complexity of logic circuits, making them more efficient in terms of speed, cost, and power consumption. Simplified expressions often result in fewer gates and connections, which can enhance the overall performance of digital systems.

What are the basic laws used to simplify Boolean expressions?

The basic laws used to simplify Boolean expressions include the Identity Law, Null Law, Idempotent Law, Complement Law, Double Negation Law, Commutative Law, Associative Law, Distributive Law, Absorption Law, and De Morgan's Theorems. These laws provide a set of rules for manipulating and reducing Boolean expressions.

How does De Morgan's Theorem help in simplifying Boolean expressions?

De Morgan's Theorem provides a way to transform complex Boolean expressions involving AND and OR operations with NOT operations. The theorems state that the complement of a conjunction is the disjunction of the complements, and the complement of a disjunction is the conjunction of the complements. This helps in converting expressions to a more simplified or standardized form.

Can you provide an example of simplifying a Boolean expression?

Sure! Consider the Boolean expression: A + AB. Using the Absorption Law, which states that A + AB = A, we can simplify this expression to just A. This reduces the complexity and number of operations required to implement the logic.

What tools or methods can be used to simplify Boolean expressions?

Several tools and methods can be used to simplify Boolean expressions, including algebraic manipulation using Boolean laws, Karnaugh maps (K-maps), and software tools like logic minimizers and computer-aided design (CAD) tools. These methods help in systematically reducing the complexity of Boolean expressions.

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