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Posted 16 Jun 2014

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# Truth Table and Simplification of a Boolean Expression

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3.00/5 (12 votes)
30 Oct 2016CPOL1 min read
Generation of Karnaugh table

## Introduction

The Karnaugh map, also known as the K-map, is a method to simplify boolean algebra.

Karnaugh maps are used to facilitate the simplification of Boolean algebra functions. Take the Boolean function described by the following truth table.

This article, and especially the attached code, is for those want to know how KARNAUGH table reduice an algebra expression.

## Requirements

The reader should have basic notions of boolean algebra; Knowledge of the Quine McKluskey algorithm is optimal. Basic notions of C# are required for understanding the code.

## Using of the Application

First, we have to introduce the boolean expression in the textbox. This one must use only (a;b:c:d;!,+) characters, then we click the button of table truth generation to fill our listview by the appropriate values.

Once the truth table is filled, we can process to generation of the Karnaugh table by clicking the button named Kanaugh.

To simplify the expression in codesource, we use two methods, the first is to simplify two terms and return the simplified expression.

C#
``` public string simplifier1(int i,int j,int order)
{
int pos = -1;
var dd = Form1.local_tab[i];
var ff = new StringBuilder(dd);
if (shift(Form1.local_tab[i], Form1.local_tab[j]) == 1)
{
ff.Remove(pos, 1);
ff.Insert(pos, "-");
lstTerms[order].SetItemChecked(i, true);
lstTerms[order].SetItemChecked(j, true);
}
return ff.ToString();
}
```

The second makes all simplifications possible in the Karnaugh table.

C#
```public void evaluer(int order)
{
int s = 0;
for (int i = 0; i < Form1.j; i++)
{
for (int k = i; k < Form1.j; k++)
{
simplifier1(i, k, order);
if ((lstTerms[order].GetItemCheckState(i) == CheckState.Checked) &&
(lstTerms[order].GetItemCheckState(k) == CheckState.Checked))
{
if (!tab.Contains(simplifier1(i, k, order)) &&
!Form1.local_tab.Contains(simplifier1(i, k, order)))
{
tab[s] = simplifier1(i, k, order);
lstTerms[order+1].Items.Add(tab[s]);
lstTerms[order+1].SetItemChecked(s, false);
s++;
}
}
}
}
for (int i = 0; i < Form1.j; i++)
{
Form1.local_tab[i] = " ";
}
Form1.j = s;
for (int i = 0; i < Form1.j; i++)
{
Form1.local_tab[i] = tab[i];
tab[i] = " ";
}
if (s == 0)
arret = true;
}
```

This is what we have as result:

### Reference an Attribution

[1} https://commons.wikimedia.org/wiki/File:K-map_minterms_A.svg

## License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

## About the Author

 Algeria
No Biography provided

## Comments and Discussions

 First Prev Next
 Thanks Phil Ouellette29-Oct-16 9:42 Phil Ouellette 29-Oct-16 9:42
 Re: Thanks Amar zaidi30-Oct-16 11:51 Amar zaidi 30-Oct-16 11:51
 My vote of 2 Philippe Mori28-Oct-16 4:19 Philippe Mori 28-Oct-16 4:19
 It might have been an interesting article.... However, they are major flaws in it: There is no explanation of what the program does.There is no clear explanation of what second form is.The capture are partially in English, partially in French.When you list characters that can be used in the text box, your separators are inconsistent (; : and ,). For 5 separators, you used 3 characters : (`a;b:c:d;!,+`).Your own code is also partly in French and partly in English.Your code does not follows usual .NET convention for naming functions.Your variables are poorly named. What id `dd`? What is `ff`?Indentation is incorrect at some place (for ex. `return` statement of `simplifier1` function.Very poor alignment in the user interface. For example, 01 (in cd column) is not aligned with 00 above it.There are some spelling errors.Code is too much tight to the user interface (UI). If one, would want to use that code with a different UI, he would have to rewrote most functions.Useless use of a `StringBuilder`. You could have used `string.Replace` instead.Poor formatting. Inconsistant use of `i`, `j` and `k` variables.Your forms have default name (Form1, Form2), instead of something meaningful.No explanation of the code in the article or as comment in code. If it was not for so many glitches, then your article would have worth 3 and if there was more explanation it would have worth 4. And with also a cleaner design, it might even have worth 5 points. Philippe Mori
 Re: My vote of 2 Amar zaidi30-Oct-16 3:06 Amar zaidi 30-Oct-16 3:06
 Missing attribution for image Jochen Arndt28-Oct-16 3:34 Jochen Arndt 28-Oct-16 3:34
 Cannot Download the ZIP File Member 1004250111-Oct-16 5:59 Member 10042501 11-Oct-16 5:59
 Re: Cannot Download the ZIP File ronen4428-Oct-16 20:30 ronen44 28-Oct-16 20:30
 download TerryM7928-Feb-15 9:19 TerryM79 28-Feb-15 9:19
 Re: download Amar zaidi30-Oct-16 12:20 Amar zaidi 30-Oct-16 12:20
 [My vote of 1] Vote 1 TonBill18-Jun-14 3:30 TonBill 18-Jun-14 3:30
 Re: [My vote of 1] Vote 1 Amar zaidi30-Oct-16 12:22 Amar zaidi 30-Oct-16 12:22
 My vote of 1 LostTheMarbles16-Jun-14 3:48 LostTheMarbles 16-Jun-14 3:48
 Re: My vote of 1 Amar zaidi30-Oct-16 12:23 Amar zaidi 30-Oct-16 12:23
 Last Visit: 31-Dec-99 19:00     Last Update: 5-Dec-21 11:02 Refresh 1

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