# OR-Notes

## J E Beasley

OR-Notes are a series of introductory notes on topics that fall under the broad heading of the field of operations research (OR). They were originally used by me in an introductory OR course I give at Imperial College. They are now available for use by any students and teachers interested in OR subject to the following conditions.

A full list of the topics available in OR-Notes can be found here.

#### Mathematical notation

When constructing OR-Notes I have tried to ensure that mathematical notation is kept to a minimum and also that most Web browsers should be able to view OR-Notes correctly.

• <= should be read as "less than or equal to"
• >= should be read as "greater than or equal to"
• SUM[i=1 to n] should be read as "sum over all integer values of i from 1 to n inclusive"
• INFINITY is used instead of an infinity sign
• PI is used instead of a pi symbol

Subscripts and superscripts should be displayed correctly by the latest versions of Netscape and Internet Explorer browsers. To check your browser:

• x1 should be "x subscript 1"
• x1 should be "x superscript 1"

The pound sterling sign should be displayed correctly by the latest versions of Netscape and Internet Explorer browsers. To check your browser:

• £ should be "the pound sterling sign"

If the above subscript, superscript and pound sterling sign are not displayed correctly then I suggest that you upgrade your browser. If this is not possible then:

• save the OR-Notes files you are interested in on your own computer
• use your favourite word processor to edit these files
• for subscripts:
• change <sub> and <SUB> to {
• change </sub> and </SUB> to }
• this will ensure all subscripts are denoted by {} e.g. x subscript i becomes x{i}
• for superscripts:
• change <sup> and <SUP> to ^{
• change </sup> and </SUP> to }
• change &sup2; to ^{2}
• change &sup3; to ^{3}
• this will ensure all superscripts are denoted by ^{} e.g. x superscript i becomes x^{i}
• for the pound sterling sign:
• change &pound; to &#163; or to \$ if you prefer to change currency;
• this will ensure that all pound sterling signs in the text appear correctly
• save the edited files as DOS ASCII text files