It is an ironic and frustrating fact that, although computers were invented by mathematicians, the one thing that is extraordinarily difficult to type on computers is mathematics. Many sophisticated word processors and desktop publishing programs do have equation editors to enter mathematical symbols but most of them are cumbersome, some are buggy and all are awkward to use especially for more than the odd formula.
Specialist software is also very expensive.
Worse still, these editors are absolutely no use when it comes to email. There's yet more bad news. With the widespread use of proportional fonts, trying to line text up using spaces can be next to useless. This is a guide to writing mathematics using only normal symbols. Much of it is a compromise and may not be satisfactory as it can be quite hard to read.