Converting between Sums of Products & Products of Sums

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SUMMARY

The discussion focuses on converting a Boolean expression from Sum of Products (SOP) to Products of Sums (POS) using DeMorgan's theorem and truth tables. The equation in question is F = (xyz' + x'w)(yz + x'z'). Participants emphasize the importance of identifying false cases through a truth table to derive maxterms, which are then negated to achieve the canonical POS form. The conversation highlights the complexity of this conversion process and clarifies that canonical form represents an unsimplified version of the equation.

PREREQUISITES
  • Understanding of Boolean algebra and canonical forms
  • Familiarity with DeMorgan's theorem
  • Ability to construct and interpret truth tables
  • Knowledge of maxterms and minterms in Boolean expressions
NEXT STEPS
  • Learn how to construct truth tables for Boolean expressions
  • Study the application of DeMorgan's theorem in Boolean algebra
  • Explore the process of converting between SOP and POS forms
  • Practice simplifying Boolean expressions using Boolean algebra rules
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Students and professionals in electrical engineering, computer science, or anyone studying digital logic design who need to understand Boolean algebra conversions and canonical forms.

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Homework Statement



Translate the following equation into canonical S of P form:
F = (xyz' + x'w)(yz + x'z')

Homework Equations


DeMorgan's theorem?
(x + y)' = x'y'
(xy)' = x' + y'

The Attempt at a Solution


Converting from Sum of Products to Products of Sums requires the following:
Since I utilize a truth table, I locate the false cases. Then I write the maxterms out for these false cases. The resulting equation is then negated and DeMorgan's theorem is utilized to solve for the new equation, which represents the product of sums.

I've tried to perform this process in reverse to determine the sum of products for this equation. However, I get stuck, as the equation itself is not a "perfect" product of sums -- there are products within the sums (such as xyz').

How do I handle this? Am I just confused by something here? Some examples I see involve expansion (almost like FOILing it out). Also, its my understanding that canonical form is an unsimplified representation of the equation. Is this correct?
 
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bphysics said:

Homework Statement



Translate the following equation into canonical S of P form:
F = (xyz' + x'w)(yz + x'z')

Homework Equations


DeMorgan's theorem?
(x + y)' = x'y'
(xy)' = x' + y'

The Attempt at a Solution


Converting from Sum of Products to Products of Sums requires the following:
Since I utilize a truth table, I locate the false cases. Then I write the maxterms out for these false cases. The resulting equation is then negated and DeMorgan's theorem is utilized to solve for the new equation, which represents the product of sums.

I've tried to perform this process in reverse to determine the sum of products for this equation. However, I get stuck, as the equation itself is not a "perfect" product of sums -- there are products within the sums (such as xyz').

How do I handle this? Am I just confused by something here? Some examples I see involve expansion (almost like FOILing it out). Also, its my understanding that canonical form is an unsimplified representation of the equation. Is this correct?

Here's a few more rules that you can use:
1. (a+b)(c+d) = ac + ad + bc + bd
2. xx'=0
3. xx=x
4. x0=0
5. yz+z'=y+z'

Note that rule 1 converts the mix of products and sums to a sum-product.

With these you don't need truth tables.:)
 
I like Serena said:
Here's a few more rules that you can use:
1. (a+b)(c+d) = ac + ad + bc + bd
2. xx'=0
3. xx=x
4. x0=0
5. yz+z'=y+z'

Note that rule 1 converts the mix of products and sums to a sum-product.

With these you don't need truth tables.:)

So why is such a "complex" method required to convert from sums of products to products of sums? Why do I need to utilize DeMorgan's theorem for this conversion?
 
bphysics said:
So why is such a "complex" method required to convert from sums of products to products of sums? Why do I need to utilize DeMorgan's theorem for this conversion?

I can't answer why - it just is.
Btw, the rules are not just abstract rules - they have meaning.
For instance, rule 2 that I gave (xx' = 0) simply says that x cannot both be true and false.

In this particular problem I do not see how you would use the laws of DeMorgan.
 

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