This section covers the Calc features that help you work with
algebraic formulas. First, the general sub-formula selection
mechanism is described; this works in conjunction with any Calc
commands. Then, commands for specific algebraic operations are
described. Finally, the flexible *rewrite rule* mechanism
is discussed.

The algebraic commands use the `a` key prefix; selection
commands use the `j` (for “just a letter that wasn’t used
for anything else”) prefix.

See Editing Stack Entries, to see how to manipulate formulas using regular Emacs editing commands.

When doing algebraic work, you may find several of the Calculator’s
modes to be helpful, including Algebraic Simplification mode (`m A`)
or No-Simplification mode (`m O`),
Algebraic entry mode (`m a`), Fraction mode (`m f`), and
Symbolic mode (`m s`). See Mode Settings, for discussions
of these modes. You may also wish to select Big display mode (`d B`).
See Normal Language Modes.