OpenLLM-France/wikimedia huggingface dataset:
# A-level Chemistry/AQA

This is the branch of the A-level Chemistry book, designed to follow the AQA specification. It is not endorsed by AQA. It will hopefully be useful as a revision guide, or for those seeking a basic grounding in the principles of the course.

## AS Units

* Module 1: Atomic Structure, Bonding and Periodicity
** Atomic Structure (Nov 23rd, 2006)
** Amount of Substance (Nov 8th 2006)
** Bonding (Nov 23rd, 2006)
** Periodicity (Nov 8th, 2006)
* Module 2: Foundation Physical and Inorganic Chemistry
** Energetics (Nov 8th, 2006)
** Kinetics (Nov 8th, 2006)
** Equilibria (Nov 30th, 2006)
** Redox Reactions (Nov 8th, 2006)
** Group VII: The Halogens (Nov 30th, 2006)
** Extraction of Metals (Nov 30th, 2006)
* Module 3: Introduction to Organic Chemistry
** Nomenclature and Isomerism (Nov 8th, 2006)
** Petroleum and Alkanes (Nov 8th, 2006)
** Alkenes and Epoxyethane (Nov 8th, 2006)
** Haloalkanes (Nov 8th, 2006)
** Alcohols (Nov 8th, 2006)
AS Chemistry Specification, 2007 Entry

## A2 Units

* Module 4: Further Physical and Organic Chemistry
** Kinetics (April 13th, 2009)
** Equilibria
** Acids and Bases
** Nomenclature and Isomerism in Organic Chemistry
** Compounds Containing the Carbonyl Group
** Aromatic Chemistry (April 13th, 2009)
** Amines
** Amino Acids
** Polymers (April 13th, 2009)
** Organic Synthesis
** Structure Determination (April 13th, 2009)
* Module 5: Thermodynamics and Further Inorganic Chemistry
** Thermodynamics (April 13th, 2009)
** Periodicity (April 13th, 2009)
** Redox equilibria (April 13th, 2009)
** Transition metals (April 13th, 2009)
** Reaction of inorganic compounds is aqeueous solution (April 13th, 2009)
# A Quick Introduction to Unix/Deleting Files

* Components
* Shells and subshells
* Directory Structure
* Changing Directories
* Listing Files and Directories
* Pathnames
* Files and Processes
* Wildcards
* Exercises 1
* Creating Directories
* Creating Files
* Special Directories
* Exercises 2
* Copying Files
* Moving Files
* Deleting Files
* Exercises 3
* Redirection
* Searching Text Files
* More grep examples
* Permissions on Files and Directories
* Editing Text
* Exercises 4
* My First Shell Script
* Job Control
* Links
* Environment Variables

## Deleting files and directories
### rm (remove)

To delete (remove) a file you use the command rm. So you might create a copy of a science.txt file and then delete it. You would type
To delete several files you may be able to use a wildcard. Consider the following command
This will delete all files in the current directory with names ending .txt. If you use extensions (the bit of the filename after the dot) systematically this can be useful.

### rmdir (remove directory)

You can use the rmdir command to remove a directory. If you have an empty directory that you no long require for example, you can type
(Of course, your directory probably isn't called someoldolddirectory but I think you get the idea.)
If however, you try to remove a directory that has files in it, you will not be able to since Unix will not let you remove a non-empty directory. The solution is to use the option –r on the rm command like this
and this will remove a directory and all its subdirectories even if they contain files. The -r stands for recursive.
# A Practical Guide to Interest Rate Derivative Modelling/Curve Calibration

(WIP)
In the previous chapters we have assumed the interest rate term structure to be given by a black-box which fits all market traded instruments. In this chapter we consider how the black-box works.
parametric Interpolation
non-parametric optimization
reference to books and open source libraries
can we go p-quant?
# A Quick Introduction to Unix/Changing Directories

* Components
* Shells and subshells
* Directory Structure
* Changing Directories
* Listing Files and Directories
* Pathnames
* Files and Processes
* Wildcards
* Exercises 1
* Creating Directories
* Creating Files
* Special Directories
* Exercises 2
* Copying Files
* Moving Files
* Deleting Files
* Exercises 3
* Redirection
* Searching Text Files
* More grep examples
* Permissions on Files and Directories
* Editing Text
* Exercises 4
* My First Shell Script
* Job Control
* Links
* Environment Variables

## Changing to different directories
### cd (change directory)

The command cd somedirectory means change the current working directory to somedirectory. The current working directory is the directory that you are currently working in.
# A Quick Introduction to Unix/Components

* Components
* Shells and subshells
* Directory Structure
* Changing Directories
* Listing Files and Directories
* Pathnames
* Files and Processes
* Wildcards
* Exercises 1
* Creating Directories
* Creating Files
* Special Directories
* Exercises 2
* Copying Files
* Moving Files
* Deleting Files
* Exercises 3
* Redirection
* Searching Text Files
* More grep examples
* Permissions on Files and Directories
* Editing Text
* Exercises 4
* My First Shell Script
* Job Control
* Links
* Environment Variables
Unix is made up of three components
* the kernel;
* the shell; and
* programs.

## The kernel

The kernel of Unix is the heart of the operating system. It allocates time and memory to programs and handles the file structure and communication between the different parts of the computer system such as the keyboard and the screen.

## The shell

The shell is an interface between the user and the Unix kernel. It resembles the ‘dos box’ that Windows displays if you run the command cmd. When a user logs in, Unix checks their username and password and then starts a program called the shell. The shell interprets the commands the user types and transmits them to the kernel to be executed. These commands are programs.
There are a variety of shells available for the various Unix systems. The expert user can customise their own shell and users can use different shells on the same machine.
The shell and kernel work together like this:
* a user types cat somefile to display a file;
* the shell finds the program cat;
* the shell instructs the kernel to run the program cat on somefile;
* When the program finishes the kernel passes control back to the shell and displays the Unix prompt.

### Which shell?

There are a number of different shells for Unix. People can become very attached to the shell they prefer. Popular shells include
* sh - the bourne shell
* bash - the bourne again shell
* csh - the c shell
* ksh - the Korn shell (strangely, not named for the band)
* zsh - the z shell
You can invoke any shell installed on your system with one of the above commands at the prompt. (Notice that this means you start a new shell within a shell!). We won't cover the distinctions about different shells at this time. When you begin to write Unix Shell Scripts you will probably want to choose a shell and stick with it if you can. Each shell has its advocates. The Bourne again shell is popular with many script writers. Some in the Unix community have expressed doubts about the suitability of the c shell for scripting, but this is something you can address when you know more about Unix (see Csh Programming Considered Harmful).
You can start a shell of a particular kind by typing the shell name at the command line prompt.

## Programs

Programs are not part of the operating system as such, but they are logical sequences of commands, developed for implementing specific tasks. They usually include application software running at the user end.
# A Quick Introduction to Unix/Creating Files

* Components
* Shells and subshells
* Directory Structure
* Changing Directories
* Listing Files and Directories
* Pathnames
* Files and Processes
* Wildcards
* Exercises 1
* Creating Directories
* Creating Files
* Special Directories
* Exercises 2
* Copying Files
* Moving Files
* Deleting Files
* Exercises 3
* Redirection
* Searching Text Files
* More grep examples
* Permissions on Files and Directories
* Editing Text
* Exercises 4
* My First Shell Script
* Job Control
* Links
* Environment Variables

## Creating Files

Files are essentially containers. You can fill a file with a variety of kinds of data, rather as you might fill a bucket with water or sand. There are occasions when the facility to create an empty bucket is useful.

### The command touch

This creates a file called my_new_file. One other use of touch is to update a file's date and time. This is done with the option -t. For example
This would update the time and date stamp for the file causing it to show the date and time 11 October 2010 at 22:30. The data and time format is yyyymmddhhmm.
You can check the effect of touch with ls -l

### Why use touch?

One very good use for touch is to help create directory and file structures. Suppose that in a university departmental office each year you must create various administrative files. You will need a file of the new students; a file of staff; a file of options offered that year and so on. From your home you might first of all create a directory to hold the student files:
and then to be sure that you have the correct file structure
and similarly for any other files and directories you need.
# A Practical Guide to Interest Rate Derivative Modelling/Fundamentals

(work in progress)
In this part we cover the following:
Part I. Market fundamentals
Chapter 1. Demand and Supply of Funds
Chapter 2. Derivatives
Chapter 3. Market Making, Hedging and Arbitrage
Chapter 4. Regulatory constraints
Part II. Modelling fundamentals (maybe merge with Part I)
Chapter 5. What a Model Does
Chapter 6. Recipe to price/value a product
Part III. Modelling Funding Transactions
Chapter 7. Single-Currency Funding and Yield Curves
Chapter 8. Cross-Currency Funding and Yield Differentials
Part IV. Modelling Derivative Transactions
Chapter 9. Interest Rate Swap and Forward Curves
Chapter 10. Basis Swap and Basis Curves
Chapter 11. Overnight Index Swap (and the Reunion of Short-rate Model and Market Model)
Chapter 12. Cross-Currency Swap
Chapter 13. OTC Particularities
Chapter 14. Futures
(??) optional content: credit default swap and survival curve (more important); inflation product (?? less important); structured product (doesn't quite fit here)
Part V. Calibration
In the previous chapters we have assumed the interest rate term structure to be given by a black-box which fits all market traded instruments. In this chapter we consider how the black-box works.
# A Practical Guide to Interest Rate Derivative Modelling/Single Currency Modelling

(work in progress)
In this part we cover the following: (in decreasing order of connection to the true needs)
- Funding transactions
- OTC Derivative transaction
- Exchange derivative transaction
For each product we discuss why it exists (supply and demand), term-sheet (with link to open source code / spec), and finally the model. Probably need to discuss the front-to-back workflow.
# A Quick Introduction to Unix/Copying Files

* Components
* Shells and subshells
* Directory Structure
* Changing Directories
* Listing Files and Directories
* Pathnames
* Files and Processes
* Wildcards
* Exercises 1
* Creating Directories
* Creating Files
* Special Directories
* Exercises 2
* Copying Files
* Moving Files
* Deleting Files
* Exercises 3
* Redirection
* Searching Text Files
* More grep examples
* Permissions on Files and Directories
* Editing Text
* Exercises 4
* My First Shell Script
* Job Control
* Links
* Environment Variables

## Copying Files
### cp (copy)

To make a new copy of some file, say file1 in the current working directory with the name file2, you can use the command cp like this
Sometimes you will wish to copy a file across directories. There are two ways you could do this. First you might use cd to get to your destination directory.
Then at the Unix prompt, type,
Don't forget to type the dot . at the end of this first command line. Remember, in Unix, the dot means the current directory.
Now you can if you wish make copies of this file in this directory in the usual way, for example
Another way to achieve the same result is to use the full, absolute pathname - that is start at the root (/) and specify all the directories in the path for the original and all the directories in the path for the destination. You might have a command looking like
Of course, it's easy to make mistakes typing long path names.

#### Copying a directory and files

You can use cp to copy a directory and the files it contains (including subdirectories and their files) to a new location. The command looks like
This makes a copy of the complete contents of the directory linux in backup/linux. The new, target, directory will be created for you.
# A Quick Introduction to Unix/Creating Directories

* Components
* Shells and subshells
* Directory Structure
* Changing Directories
* Listing Files and Directories
* Pathnames
* Files and Processes
* Wildcards
* Exercises 1
* Creating Directories
* Creating Files
* Special Directories
* Exercises 2
* Copying Files
* Moving Files
* Deleting Files
* Exercises 3
* Redirection
* Searching Text Files
* More grep examples
* Permissions on Files and Directories
* Editing Text
* Exercises 4
* My First Shell Script
* Job Control
* Links
* Environment Variables

## Creating Directories
### mkdir (make directory)

You can make a subdirectory of your home directory for your own data files. To make a subdirectory called mytraining in your current working directory type
To see the directory you have just created, type
You can also make a hidden directory if you want to. Use a dot as the first character of the directory name for it to be hidden.

#### Creating down a path

Surprisingly often you want to create a directory but not directly at your current position in the directory tree. Suppose I am in my home directory and I want to create directories to hold some files for two courses but in
The first course is an introduction to Linux, second an introduction to Solaris. I can create these directories like this:
and
Naturally, you don't have to specify the complete path from ~, but I have done so here for clarity.

#### Creating a whole path

mkdir -p
Perhaps less often you want to create not a single directory but rather a directory subtree - that is a directory and directories beneath it. Suppose I am in my home directory and I want to create directories to hold some files for two courses: Redhat for Beginners and Advanced Redhat. We can do this with the -p option on the mkdir command.
Here is the command to create the first directory:
This creates the two directories we require in one go. We can then issue the command
Notice the difference between these two.
# A-level Computing/AQA/Paper 2/Fundamentals of communication and networking

* TCP-IP
* Standard application layer protocols
* IP standards
* IP address structure
* Subnet masks
* Public and private IP addresses
* Network Address Translation (NAT)
* Port forwarding
* Dynamic Host Configuration Protocol (DHCP)
* Client server model
* Thin versus thick client computing
# A-level Computing/AQA/Paper 2/Fundamentals of communication and networking/Dynamic Host Configuration Protocol (DHCP)

DHCP (Dynamic Host Configuration Protocol) is a method of automatically allocating IP addresses to machines on a 'need to use' basis. Rather than have every machine in the network given a fixed IP address we allocate IP addresses to those machines as and when they connect. The key word in DHCP is "dynamic." - instead of having just one fixed, specific IP address, most computers will be assigned one that is available from a subnet or "pool" that is assigned to the network.

## Stages of DHCP
### Stage 1

When a host wants to join a DHCP network it will broadcast a DHCP discovery message over the network. At this point the host doesn't know the IP address or subnet of the DHCP host, so it will broadcast to all the nodes on the network

### Stage 2

The DHCP server will respond to the message that the new node is broadcasting and send a reply containing a proposed IP address, network mask, lease time and a transaction ID. It would then record this information in its own datastore.

### Stage 3

The new node must accept this offer

### Stage 4

The new node and DHCP server then confirms the requested parameters

## Advantages of DHCP

* It is possible to have more machines than available IP addresses on the assumption that everyone wont be using the network at once.
* We don't have to manually assign IP addresses and so saves time and avoids the possibility of accidentally assigning the same IP address twice.

## Disadvantages of DHCP

* Tracing internet activity may be difficult as the same machine may have two or more different IP addresses over a period of time.
* Not having a static IP means computers with DHCP cannot be used as servers as their IP will change
# A-level Computing/AQA/Paper 2/Fundamentals of algorithms/

Description here...
# A-level Computing/AQA/Paper 2/Fundamentals of communication and networking/Communication methods
### Key definitions

Serial data transmission is when bits are sent one bit at a time over a single wire when transmitting data.
Parallel data transmission is when bits are sent concurrently over a number of parallel wires. This is specifically used in integrated circuits with RAM.
Synchronous transmission is where data is sent at regular intervals that are timed by a clock signal to allow for a more reliable transfer of data.
Asynchronous transmission is where data is sent one byte at a time with each character starting with a start bit and ending with a stop and parity bit.

### Advantages of serial over parallel transmissions

* There is a huge reduction in size and complexity, allowing the cost to be less.
* The "crosstalk" between parallel lines creates corrupted data transmissions easily. As the signal frequency increases, the worse the communication link becomes.
* Serial is more reliable over distances, as the "crosstalk" worsens over distances with parallel.
* Signal frequencies have the potential to be higher due to lack of interference.

### The importance of start and stop bits

By using a start and stop bit, the receiver is able to discern when the next set of data is sent and ends, allowing for only one byte of data to be sent at a time.
# A-level Mathematics/MEI/NM/Integration

Doing definite integrals can be seen as just finding the area under a curve on a graph. You may have met elsewhere the idea of finding the area of complicated shapes by splitting them up into simpler shapes that we can easily calculate the areas of. We use a similar technique for numerical integration - we approximate the curve by a series of simple shapes and add up the areas of these to get a value for the integral.

## Mid-point rule

This method approximates the curve using rectangles. The height of each rectangle is given by the value of the function in the middle of the rectangle, and all the rectangles have the same width.
We divide the interval [a, b] to integrate over into n strips of equal width. The width of each strip is then h = (b - a)/n.
We write the value of x at a as x$_0$, at the end of the first rectangle as x$_1$, at the end of the second as x$_2$, and so on. x$_r$ is the value of x at the right hand side of r strips, so x$_r$ = a + r * h.
Also note that f(x) evaluated at x$_0$ can be written as f$_0$, at x$_1$ as f$_1$, and so on. The value of f(x) evaluated at x$_r$ is f$_r$.
The area of each approximating rectangle is h multiplied by f(x) evaluated in the middle of the rectangle. Following on from the above notation, the value of f(x) evaluated halfway through the first strip is f$_{0.5}$, so the area of the approximating rectangle for the first strip is h f$_{0.5}$.
Therefore, for n strips, the total area is:
$\int \limits _{a}^{b}f(x)\,dx\approx h(f_{0.5}+f_{1.5}+\ldots +f_{n-1.5}+f_{n-0.5})$
# Sections

* The trapezium and midpoint rules
* Simpson's rule
# A-level Mathematics/MEI/S1
## Statistics 1 (S1) MEI Course

The Statistics 1 course introduces A -Level Students to the following topics:
* Presenting Data - Cumulative Frequency, use of graphs|Presenting Data - Cumulative Frequency, use of graphs
* Exploring Data - Standard Deviation, Root Mean Squared Deviation, Mean, Averages.
* Probability - Independent/Mutually Exclusive events. Introduction to Notation. Conditional Probability
* Discrete Random Variables - Use of variables to show the probability of a particular result. Expectation and Variance.
* Further Probability - Permutations and Combinations.
* The Binomial Distribution - E(X) = np and Var(x) = npq
* Hypothesis Testing using the Binomial Distribution - Accepting/Rejecting Ho
# Sections

* Forward & central differences
# Sections

* Sequences
* Integration and differentiation
# Sections

* Interval bisection
* Fixed-point iteration
* Convergence
* Newton-Raphson & secant methods
* The method of false position
# A-level Mathematics/MEI/S1/Discrete Random Variables
## Discrete Random Variables

Discrete random variables are the models for the probabilities of particular results. They are represented by the notation, $P(X=R)$ (Where P is the probability of the Discrete Random Variable, X , taking on the result, R.). A discrete random variable can only take on the values r$_1$,r$_2$,r$_3$...r$_n$ with the probabilities p$_1$, p$_2$, p$_3$...p$_n$ respectively. Discrete random variables allow us to produce a Discrete Frequency Distribution. Discrete meaning that the value of the results can only take on positive whole integers. In S1, Discrete distributions are limited to a finite number of outcomes.

## Exemplar Question

Questions often involve working with algebra in order to find the probabilities, in OCR(MEI), you will often have to work out the value of k in order to work out the probabilities.
The probability distribution of a discrete random variable, X, is given by
Find the value of k and tabulate the probability distribution.
To find the value of k, we need to tabulate our probabilities and substitute the values of R into the discrete random variable, X.
# A-level Mathematics/MEI/S1/The Binomial Distribution

Conditions for a situation to be normally distributed
If a situation is to be binomially distributed it must satisfy the following conditions.
1. The event must have only two possible outcomes.The outcomes are normally termed as 'success' ( denoted by $p$ ) and failure ( denoted by $q$ )
2. The two outcomes must be independent.

## Converting Binomial distribution into a Normal Distribution

If an event is to be repeated $n$ number of times with constant (independent) probabilities of both the possible outcomes occurring, by calculating the mean ($n*p$ ) of the distribution and the variance ( $n*p*q$ ) of the distribution, the binomial distribution can be converted into an approximate normal distribution.
# Axis & Allies

Axis and Allies is a series of World War II-themed grand strategy games published by Milton Bradley. The first game in the series was released in 1981, and several different versions and spinoffs of the game have been released since then. This book will detail the rulesets for some of the games in the Axis and Allies series.
This is a collaborative book to which anyone can contribute.
Notable versions of Axis and Allies:
* Axis & Allies Classic
* Axis & Allies: 1942
* Axis & Allies: 1941
* Axis & Allies: 1940
** Europe 1940
** Pacific 1940
** Global 1940
* Axis & Allies: WWI 1914
* Axis & Allies & Zombies
Notable spin-offs:
* Axis & Allies: D-Day
* Axis & Allies: Battle of the Bulge
* Axis & Allies: Guadalcanal