Converting between Sums of Products & Products of Sums

  • Thread starter Thread starter bphysics
  • Start date Start date
  • Tags Tags
    Sums
Click For Summary

Homework Help Overview

The discussion revolves around converting a logical equation from Sum of Products (S of P) form to Products of Sums (P of S) form, specifically the equation F = (xyz' + x'w)(yz + x'z'). Participants explore the implications of canonical forms and the application of DeMorgan's theorem in this context.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the process of using truth tables to identify false cases and the subsequent steps to derive maxterms. There is confusion regarding the presence of products within sums and how to handle them in the conversion process. Questions arise about the necessity of DeMorgan's theorem and the complexity of the conversion method.

Discussion Status

The discussion is active, with participants sharing their attempts and questioning the methods involved. Some guidance has been offered regarding rules for conversion, but there is no explicit consensus on the best approach to take. The complexity of the conversion process remains a point of contention.

Contextual Notes

Participants note that canonical form is understood to be an unsimplified representation of the equation, and there is an ongoing examination of the rules and their meanings in the context of the problem.

bphysics
Messages
33
Reaction score
0

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?
 
Physics news on Phys.org
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.
 

Similar threads

Replies
31
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
5
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
2
Views
4K