OpenLLM-France/wikimedia huggingface dataset:
# Character Encodings/Code Tables/EBCDIC/EBCDIC 394

IBM code page 394 is an EBCDIC code page used in IBM mainframes. It is called Publishing: United Kingdom or Publishing: United Kingdom, Australia, Hong Kong, Ireland, New Zealand. This code page is supported by IBM. It is a modification of EBCDIC 361.
EBCDIC 394 :
| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
| 4x | SP | | â 00E2 | ä 00E4 | à 00E0 | á 00E1 | ã 00E3 | å 00E5 | ç 00E7 | ñ 00F1 | $ 0024 | . 002E | < 003C | ( 0028 | + 002B | | 007C |
| 5x | & 0026 | é 00E9 | ê 00EA | ë 00EB | è 00E8 | í 00ED | î 00EE | ï 00EF | ì 00EC | ß 00DF | ! 0021 | £ 00A3 | * 002A | ) 0029 | ; 003B | ¬ 00AC |
| 6x | - 002D | / 002F | Â 00C2 | Ä 00C4 | À 00C0 | Á 00C1 | Ã 00C3 | Å 00C5 | Ç 00C7 | Ñ 00D1 | ] 005D | , 002C | % 0025 | _ 005F | > 003E | ? 003F |
| 7x | ø 00F8 | É 00C9 | Ê 00CA | Ë 00CB | È 00C8 | Í 00CD | Î 00CE | Ï 00CF | Ì 00CC | | : 003A | # 0023 | @ 0040 | ' 0027 | = 003D | " 0022 |
| 8x | Ø 00D8 | a 0061 | b 0062 | c 0063 | d 0064 | e 0065 | f 0066 | g 0067 | h 0068 | i 0069 | « 00AB | » 00BB | ‰ 2030 | − 2212 | ĳ 0133 | ﬃ FB03 |
| 9x | ° 00B0 | j 006A | k 006B | l 006C | m 006D | n 006E | o 006F | p 0070 | q 0071 | r 0072 | — 2014 | Œ 0152 | æ 00E6 | Ÿ 0178 | Æ 00C6 | ● 25CF |
| Ax | ﬀ FB00 | | s 0073 | t 0074 | u 0075 | v 0076 | w 0077 | x 0078 | y 0079 | z 007A | ¡ 00A1 | ¿ 00BF | œ 0153 | ﬄ FB04 | ‡ 2021 | „ 201E |
| Bx | ¢ 00A2 | [ 005B | ¥ 00A5 | ﬁ FB01 | ﬂ FB02 | § 00A7 | ¶ 00B6 | ¼ 00BC | ½ 00BD | ¾ 00BE | ⅛ 215B | ‘ 2018 | ’ 2019 | “ 201C | ” 201D | † 2020 |
| Cx | { 007B | A 0041 | B 0042 | C 0043 | D 0044 | E 0045 | F 0046 | G 0047 | H 0048 | I 0049 | | ô 00F4 | ö 00F6 | ò 00F2 | ó 00F3 | õ 00F5 |
| Dx | } 007D | J 004A | K 004B | L 004C | M 004D | N 004E | O 004F | P 0050 | Q 0051 | R 0052 | ⅜ 215C | û 00FB | ü 00FC | ù 00F9 | ú 00FA | ÿ 00FF |
| Ex | \ 005C | | S 0053 | T 0054 | U 0055 | V 0056 | W 0057 | X 0058 | Y 0059 | Z 005A | ⅝ 215D | Ô 00D4 | Ö 00D6 | Ò 00D2 | Ó 00D3 | Õ 00D5 |
| Fx | 0 0030 | 1 0031 | 2 0032 | 3 0033 | 4 0034 | 5 0035 | 6 0036 | 7 0037 | 8 0038 | 9 0039 | ⅞ 215E | Û 00DB | Ü 00DC | Ù 00D9 | Ú 00DA | EO |
| Differences from EBCDIC 361 |||||||||||||||||

## References

* ↑ z/OS Font Collection, Summary tables for code pages, IBM
* ↑ "Summary tables for code pages" (PDF), Ricoh InfoPrint Font Collection, Font Summary, Ricoh, pp. 121–132
* ↑ https://web.archive.org/web/20120716195651/http://www-03.ibm.com/systems/i/software/globalization/codepages.html. {{cite web}}: Missing or empty |title= (help)
* ↑ "Code Page CPGID 00394 (pdf)" (PDF). Archived from the original (PDF) on 2015-07-08.
* ↑ Borgendale, Ken, OS/2 codepages by category, Other EBCDIC codepages, Codepage 394 - United Kingdom - Publishing
# Character Encodings/Code Tables/EBCDIC/EBCDIC 395

IBM code page 395 is an EBCDIC code page used in IBM mainframes. It is called Publishing: United States or Publishing: United States, Canada. This code page is supported by IBM. It is a modification of EBCDIC 361.
EBCDIC 395 :
| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
| 4x | SP | | â 00E2 | ä 00E4 | à 00E0 | á 00E1 | ã 00E3 | å 00E5 | ç 00E7 | ñ 00F1 | ¢ 00A2 | . 002E | < 003C | ( 0028 | + 002B | | 007C |
| 5x | & 0026 | é 00E9 | ê 00EA | ë 00EB | è 00E8 | í 00ED | î 00EE | ï 00EF | ì 00EC | ß 00DF | ! 0021 | $ 0024 | * 002A | ) 0029 | ; 003B | ¬ 00AC |
| 6x | - 002D | / 002F | Â 00C2 | Ä 00C4 | À 00C0 | Á 00C1 | Ã 00C3 | Å 00C5 | Ç 00C7 | Ñ 00D1 | ] 005D | , 002C | % 0025 | _ 005F | > 003E | ? 003F |
| 7x | ø 00F8 | É 00C9 | Ê 00CA | Ë 00CB | È 00C8 | Í 00CD | Î 00CE | Ï 00CF | Ì 00CC | | : 003A | # 0023 | @ 0040 | ' 0027 | = 003D | " 0022 |
| 8x | Ø 00D8 | a 0061 | b 0062 | c 0063 | d 0064 | e 0065 | f 0066 | g 0067 | h 0068 | i 0069 | « 00AB | » 00BB | ‰ 2030 | − 2212 | ĳ 0133 | ﬃ FB03 |
| 9x | ° 00B0 | j 006A | k 006B | l 006C | m 006D | n 006E | o 006F | p 0070 | q 0071 | r 0072 | — 2014 | Œ 0152 | æ 00E6 | Ÿ 0178 | Æ 00C6 | ● 25CF |
| Ax | ﬀ FB00 | | s 0073 | t 0074 | u 0075 | v 0076 | w 0077 | x 0078 | y 0079 | z 007A | ¡ 00A1 | ¿ 00BF | œ 0153 | ﬄ FB04 | ‡ 2021 | „ 201E |
| Bx | [ 005B | £ 00A3 | ¥ 00A5 | ﬁ FB01 | ﬂ FB02 | § 00A7 | ¶ 00B6 | ¼ 00BC | ½ 00BD | ¾ 00BE | ⅛ 215B | ‘ 2018 | ’ 2019 | “ 201C | ” 201D | † 2020 |
| Cx | { 007B | A 0041 | B 0042 | C 0043 | D 0044 | E 0045 | F 0046 | G 0047 | H 0048 | I 0049 | | ô 00F4 | ö 00F6 | ò 00F2 | ó 00F3 | õ 00F5 |
| Dx | } 007D | J 004A | K 004B | L 004C | M 004D | N 004E | O 004F | P 0050 | Q 0051 | R 0052 | ⅜ 215C | û 00FB | ü 00FC | ù 00F9 | ú 00FA | ÿ 00FF |
| Ex | \ 005C | | S 0053 | T 0054 | U 0055 | V 0056 | W 0057 | X 0058 | Y 0059 | Z 005A | ⅝ 215D | Ô 00D4 | Ö 00D6 | Ò 00D2 | Ó 00D3 | Õ 00D5 |
| Fx | 0 0030 | 1 0031 | 2 0032 | 3 0033 | 4 0034 | 5 0035 | 6 0036 | 7 0037 | 8 0038 | 9 0039 | ⅞ 215E | Û 00DB | Ü 00DC | Ù 00D9 | Ú 00DA | EO |
| Differences from EBCDIC 361 |||||||||||||||||

## References

* ↑ z/OS Font Collection, Summary tables for code pages, IBM
* ↑ "Summary tables for code pages" (PDF), Ricoh InfoPrint Font Collection, Font Summary, Ricoh, pp. 121–132
* ↑ https://web.archive.org/web/20120716195651/http://www-03.ibm.com/systems/i/software/globalization/codepages.html. {{cite web}}: Missing or empty |title= (help)
* ↑ "Code Page CPGID 00395 (pdf)" (PDF). Archived from the original (PDF) on 2015-07-08.
* ↑ Borgendale, Ken, OS/2 codepages by category, Other EBCDIC codepages, Codepage 395 - United States - Publishing
# Electrodynamics/Introduction
## Welcome

Welcome to the Electrodynamics wikibook. This book is a wiki, so all readers are welcome to contribute to the book to help make it better.

## Who is this book for?

This book is part of a series of books on Modern Physics, and is intended to be read by advanced undergraduate students in the fields of physics or engineering.

## What will this book cover?

This book is going to introduce and discuss the topics of the electric field and the magnetic field. We are going to discuss the effects of relativity on these fields. We are also going to introduce tensors as a method to describe these fields under transformation.

## What are the prerequisites?

Before reading this book, the reader should have a solid background in calculus (especially multivariable or "vector" calculus), differential equations, and elementary physics. Some books that will be useful are:
* Calculus
* Ordinary Differential Equations
* Linear Algebra
* Real Analysis
* Engineering Analysis

## Notations

This book will rely on a variety of mathematical notations. We will follow this convention, where possible:
* Scalars will be italic. Scalars will be denoted with a lower-case letter, or a Greek letter.
* Vectors will be bold and lower-case.
* Vector fields, tensors, and matrices will be bold and upper-case.
* A cross (×) will denote the vector cross-product, not scalar multiplication.
* Where possible, when an equation or mathematical term needs to be embedded in the text of a page, it will be rendered as HTML, not in TeX.
* Parenthesis will be used to denote the arguments to a function, such as σ(r). Subscripts will be used to denote elements from inside a vector, such as p$_1$ for numbered elements, and B$_x$ for elements that correspond to a particular coordinate.
| Electrodynamics | Electrodynamics/Vector Calculus Review → |
# Electrodynamics/Electromagnetic Field Tensors

Before discussing Maxwell's Equations, it's useful to define two tensors for the Electromagnetic field. These two tensors will be used in the remainder of the book for several applications, including Maxwell's Equations.

## Field Tensors

We will define two field tensors, F and G, and we will define another tensor, σ, that we can use to generate one field tensor from the other.
    $\mathbb {F} ={\begin{bmatrix}0&B_{z}&-B_{y}&-iE_{x}\\-B_{z}&0&B_{x}&-iE_{y}\\B_{y}&-B_{x}&0&-iE_{z}\\iE_{x}&iE_{y}&iE_{z}&0\end{bmatrix}}$
    $\mathbb {G} ={\begin{bmatrix}0&E_{z}&-E_{y}&-iB_{x}\\-E_{z}&0&E_{x}&-iB_{y}\\E_{y}&-E_{x}&0&-iB_{z}\\iB_{x}&iB_{y}&iB_{z}&0\end{bmatrix}}$

## Completely Antisymmetrical Tensor

We can define a completely antisymmetrical tensor of the fourth rank (4 dimensional, so we cannot visualize it) as follows:
    $\sigma _{\mu \nu \lambda \rho }=0$ if any two indices are the same.
    $\sigma _{1234}=1$
    $\sigma _{\mu \nu \lambda \rho }=1$if the indices are all different, and if the total difference in the indices from 1234 is even.
    $\sigma _{\mu \nu \lambda \rho }=-1$if the indices are all different and if the total difference in the indices from 1234 is odd.
We can define the two field tensors, F and G in terms of this new tensor as:
    $\mathbb {G} ={\frac {i}{2}}\sum \sigma _{\mu \nu \lambda \rho }\mathbb {F} _{\lambda \rho }$
# Electrodynamics/Kirchoff's Laws

Two laws by Kirchoff are commonly used in circuit analysis. The first is known as Kirchoff's current law, and the second one is Kirchoff's voltage law.
Kirchoff's Current Law
Kirchoff's Current Law states that the sum of the currents entering a wikt:node (the point where two or more circuit elements meet) is equal to zero, with the understanding that current flowing out of a node represents a negative number. An equivalent statement of the law is that or the sum of all currents leaving the node equals the sum of all currents entering the node. This law is in fact a statement of the conservation of charge in a circuit.
Kirchoff's Second Law
Kirchoff's Voltage Law states that the sum of the voltages\potential differences in a loop or mesh equals zero. This law is a statement of the conservation of energy, because 1 volt represents the energy associated with one unit of charge passing through that point.
# Electrodynamics/Electric Energy
## Introduction

Many objects in this universe are conservative, the charge of the universe for instance always remains constant. This is called Global Conservation of Charge. But also, if you take a defined area, then the charge in that also remains constant unless some is leaving through its boundary. And if some charge is moving through the boundary, then it must be equal to the change in charge in the volume. Just like if you and your friends are in a room, you cannot just not be in the room, you must go out the door.
This is called Local Conservation of Charge.

## Charge Conservation

Let's look at the total charge enclosed by a volume V:
    $Q_{enc}(t)=\int _{V}\rho (\mathbf {r} )dV$
We'll say that the charge inside V changes according to the equation
    ${\frac {dQ_{enc}}{dt}}=\int _{V}{\frac {\partial \rho (\mathbf {r} )}{\partial t}}dV$
We could consider a current through a closed service, the boundary of V ( $\partial V$ ) for example, which would be
    $I=\int _{\partial V}\mathbf {J} \cdot \mathbf {\hat {n}} dS$
We can now bring in the equation $I={\frac {dQ}{dt}}$ and relate it to the enclosed charge. We see that the corresponding equation is
    $-{\frac {dQ_{enc}}{dt}}=\int _{\partial V}\mathbf {J} \cdot \mathbf {\hat {n}} dS$
Because there positive flux of the current density (charge leaving V) when the enclosed charge is decreasing.
We see that
    $-\int _{V}{\frac {\partial \rho (\mathbf {r} )}{\partial t}}dV=\int _{\partial V}\mathbf {J} \cdot \mathbf {\hat {n}} dS$
Then by using the divergence theorem on the right hand side, we get the law of local conservation of charge or the continuity equation.
[Law of Local Conservation of Charge]
    ${\frac {d\rho }{dt}}+\nabla \cdot \mathbf {J} =0$

## Conservation of Energy

[Law of Conservation of Energy]
    ${\frac {\partial }{\partial t}}(u_{mechanical}+u_{electromagnetic})=-\nabla \cdot \mathbf {S}$
Where
    $\mathbf {S} ={\frac {1}{\mu _{0}}}(\mathbf {E} \times \mathbf {b} )$
# Electrodynamics/Electrostatic Stress Tensor
## Force on a Charge

When we want to discuss the force on a charge due to a charge distribution, there are two options. The first is a more traditional method: an integral over a volume containing the charge distribution. The second method is less traditional but is easier to do: a surface integral over a special stress tensor.

## Volume Integral Version

    $\mathbf {F} =\int _{V}\rho \mathbf {E} dV$

## Electrostatic Stress Tensor

    $\mathbb {T} _{E}={\frac {1}{4\pi }}{\begin{bmatrix}E_{x}^{2}-{\frac {E^{2}}{2}}&E_{x}E_{y}&E_{x}E_{z}\\E_{x}E_{y}&E_{y}^{2}-{\frac {E^{2}}{2}}&E_{y}E_{z}\\E_{x}E_{z}&E_{y}E_{z}&E_{z}^{2}-{\frac {E^{2}}{2}}\end{bmatrix}}$

## Surface Integral Version

    $\mathbf {F} =\int _{S}\mathbb {T} \mathbf {n} dA$

## The Maxwell Stress Tensor

T$_{ij}$ is called the Maxwell Stress Tensor, it has two indices and is not a vector so is given a double arrow.
    $\mathbb {T} _{ij}=\epsilon _{0}\left(E_{i}E_{j}-{\frac {1}{2}}\delta _{ij}E^{2}\right)+{\frac {1}{\mu _{0}}}\left(B_{i}B_{j}-{\frac {1}{2}}\delta _{ij}B^{2}\right)$
# Digital Signal Processing

With the explosion of digital communications and digital media, the need for methods to process digital data is more important than ever. This book will begin with a look at the mathematical concepts behind digital processing, then will build on that with particular algorithms to do the work, and finally will present the actual implementations of these techniques in today's hardware and software systems. Many real-world algorithms are based on the techniques described in this book. JPEG images, MP3 songs, MPEG-2 videos, and ZIP files are all processed using digital processing techniques, and all of them will be discussed, at least conceptually. This book will not teach programming, and will probably not even provide much in the way of actual code, so we don't need to worry much about computer language dependence, except where otherwise noted. For some solid background information on the various mathematical theories in this book, consider reading Signals and Systems.
This book is in a very early stage of production, and many of the pages either don't exist or only exist as bare stubs. Help and contributions from all wikibookians will be very much appreciated!

## Table of Contents

* Introduction
* Software tools

### Digital Signals

* Discrete Data
* Discrete Operations
* Digital Systems
* Impulse Response
* Sampling and Reconstruction

### Transforms

* Continuous-Time Fourier Transform (CTFT)
* Discrete-Time Fourier Transform (DTFT)
* Discrete Fourier Transform (DFT)
* Fourier Series Expansion (FSE)
* Z Transform
* Hilbert Transform
* Fast Fourier Transform (FFT) Algorithm

### Digital Filters

* Digital Filters
* FIR Filter Design
* IIR Filter Design
* Filter Representation
* Tunable Filters
* Infinite Input Filtering
* Computer-aided Filter Design
* Ideal Filters
* Least Squares Design

### Analog Filter Modeling

* Analog Filter Design
* Spectral Transforms
* Analog Mappings
* Bilinear Transform

### Digital Processing

* Discrete Cosine Transform
* Haar Transform
* Quantization
* Multirate DSP
* Windowing

### Filter Implementation

* Filter Verification
* Implementability

### Modulation

* Phase Modulation
* Sigma-Delta modulation

### Noise and Errors

* Finite wordlength effects
* Clipping
* Quantization Effects
* Roundoff errors
* Limit Cycles
* Discrete Stochastic Process
channel of noises

### Multirate Systems

* Upsampling and Downsampling
* Multirate Filters
* Decimation and Interpolation
* Polyphase decomposition

### Advanced Filters

* Dynamic Range Scaling
* Filter Sensitivity

### Spectral Analysis

* Classical
* nonparametric
* Parametric
* Linear Prediction

### Adaptive filters

* Wiener Filters
* Normal Equations
* Kalman Filtering

### Applications

* DSP Programming
* Sound Processing
* Image Processing
* Digital Signal Processors

### Appendices

* Transforms

## Resources and Licensing

* Resources
* Licensing
# Digital Signal Processing/Analog Filter Design

It may seem strange to have a section devoted to analog filter design in a digital signal processing book. However, there is a method to the madness. It turns out that digital filters can be modeled using analog filters, and analog techniques—which have been studied in depth for many years prior to digital systems—can be utilized to quickly and efficiently design digital filters.
The following chapters will show some of the techniques involved in designing analog filters, and transforming analog filters from one type to another. The section will culminate on a chapter on the bilinear transform, which transforms the mathematical representation for an analog filter into the equations for an equivalent digital filter.

## Analog Design Process

Digital filters can be designed using analog design methods by following these steps:
* Filter specifications are specified in the digital domain. The filter type (highpass, lowpass,bandpass etc.) is specified.
* An equivalent lowpass filter is designed that meets these specifications.
* The analog lowpass filter is transformed using spectral transformations into the correct type of filter.
* The analog filter is transformed into a digital filter using a particular mapping.
There are many different types of spectral transformations and there are many mappings from analog to digital filters. the most famous mapping is known as the bilinear transform, and we will discuss that in a different chapter.

## Butterworth

Butterworth ensures a flat response in the passband and an adequate rate of rolloff. A good "all rounder," the Butterworth filter is simple to understand and suitable for applications such as audio processing.

## Chebyshev I

The Chebyshev 1 filter has ripple in the passband of the filter.

## Chebyshev II

Chebyshev 2 has ripple in the stopband.

## Elliptic

This filter has equiripple (the same amount of ripple in the passband and stopband).

## Further reading

* Signals and Systems
# Digital Signal Processing/Analog Mappings

There are a number of different mappings from the analog domain to the digital domain, and vice versa. All mappings must satisfy the following rules:
* Stability must be preserved in both domains. This means that the interior of the unit circle in the digital domain must correspond to the left-half plane in the analog plane.
* The mapping must be one-to-one. every point in one domain must correspond to a unique point in the other domain. This relationship should hold both ways.
The relationship between the analog and digital domains is highly nonlinear, and there is no way to perfectly reproduce an analog filter in a digital system, or to reproduce a digital filter in an analog system. However, it is possible to faithfully reproduce (within a certain tolerance) the magnitude response of the filter. It is rarely possible to reproduce the phase response of a filter across the transformation, however.
# Slav Defence Exchange Variation
### 4. cxd5

After this move, the tension in the center is relieved, often allowing black equality. Because of this, this variation often ends in a draw.
Black's only decent move is to complete the exchange of pawns with 4...cxd5. After the exchange, black will find it difficult to win unless white is overly ambitious.
End in the D14 exchange symmetrical is the same : the draw. Blacks and whites developing their pieces in the same way, exchanging them one after another.

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. cxd5 cxd5
| | 4 | 5 | 6 | 7 | 8 | 9 |
| Exchange Variation D13 | cxd5 cxd5 | Nc3 Bf5 | = | |
| Exchange Variation D13 | cxd5 cxd5 | Nc3 a6 | Ne5 ... | = | |
| Exchange Variation D13 | cxd5 cxd5 | Nc3 a6 | Bf4 ... | = | |
| Exchange Variation D13 | cxd5 cxd5 | Nc3 Nc6 | Bf4 e6 | e3 Be7 | = | |
| Symmetrical line D14 with 5. Nc3 Nc6 6. Bf4 BF5 7. e3 e6 | |
| | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Exchange Variation D14 | cxd5 cxd5 | Nc3 Nc6 | Bf4 Bf5 | e3 a6 | = | |
| Trifunovic Variation D14 | cxd5 cxd5 | Nc3 Nc6 | Bf4 Bf5 | e3 a6 | Qb3 Bb4 | = | |
| Symmetrical main line D14 | cxd5 cxd5 | Nc3 Nc6 | Bf4 Bf5 | e3 a6 | Bd3 Bxd3 | Qxd3 Bd6 | Bxd6 Qxd6 | O-O O-O | Rfc1 Rfc8 | = |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.
# Queen's Gambit Declined
### 3...e6
## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
1. d4 d5 2. c4 c6 3. Nf3 e6
| | 3 | 4 | 5 | 6 |
| Queen's Gambit Declined Semi-Slav | Nc3 Nf6 | = to 3. Nc3 e6 4. Nf3 |
| | e3 Nf6 | += |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* This Chess related article is a stub. Please assist Wikibooks by expanding it.
# Slav Accepted Alapin Variation

The advance of the a-pawn prevents Black from controlling b5 which in turn leaves the c4 pawn available for capture.

## Theory table

1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5. a4
| | 5 |
| Czech defence | ... Bf5 |
| Steiner variation | ... Bg4 |
| Soultanbeieff variation | ... e6 |
| Smyslov variation | ... Na6 |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.
# Chess Opening Theory/1. d4/1...d5/2. c4/2...dxc4/3. Nc3/3...f5
## 3...f5?

This move is too weakening. It weakens the entire e-file, and the c4-g8 diagonal. In Match 1, Game 8, Labourdonnais-McDonnell, McDonnell played f5 and lost quickly.

## Labourdonnais-McDonnell

* d4 d5 2. c4 dxc4 3. Nc3 f5? 4. e3 e6 5. Bxc4 c6 6 Nf3 Bd6 7 e4 b5 8. Bb3 a5 (Horrible, but he had a very bad game in any case) 9 exf5 exf5 (The open e-file, central king and open a2-g8 Diagonal promise a quick and painful demise for black). 10. O-O a4 11. Bxg8 Rxg8 12. Bg5 Qc7 13. Qe2+?! (Re1+! was much stronger) Kf8 (Kf7 was better, though after Rfe1, White's advantage is beyond dispute) 14. Rfe1 Kf7 15. Rac1 Qb7 16 d5! h6 17. dxc6 Qa6 18. Nxb5 hxg5 19. Nxd6+ Kg6 20. Ne5+ Kf6 21. Qh5 g6 22. Qh7 Be6 23. Nxg6 Nxc6 24. Rxc6 Qd3 25. Qe7+ Kxg6 26. Rxe6+ Kh5 27. Qh7+ Kg4 28. Rc4+ f4 29. h3+ Qxh3 30. Qxh3#
When contributing to this Wikibook, please follow the Conventions for organization.
# Queen's Gambit Accepted
### 3. Nf3

This is the classical continuation. White pursues its development and increases control over the e5 square. Black's main reply is 3...Nf6.

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
1. d4 d5 2. c4 dxc4 3. Nf3
| 3 |
| ... Nf6 | = |
| ... c6 | += |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.
# Chess Opening Theory/1. d4/1...d5/2. c4/2...dxc4/3. Nf3/3...Nf6
## 3...Nf6

Black develops and prevents White from establishing a pawn center with e4.

## Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation. .
1. d4 d5 2. c4 dxc4 3. Nf3 Nf6
| 4 | 5 | 6 |
| e3 Nc6 | Bxc4 e6 | Nc3 Bd6 | += |
| Nc3 Bf5 | e3 e6 | Bxc4 Nc6 | = |
| Qa4+ Nc6 | Nc3 Nd5 | Ne5 Nb6 | = |
When contributing to this Wikibook, please follow the Conventions for organization.

## References

* Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.