Editing Canonical normal form (section)

=== Indexing minterms ===
There are 2<sup>''n''</sup> minterms of ''n'' variables, since a variable in the minterm expression can be in either its direct or its complemented form—two choices per variable. Minterms are often numbered by a binary encoding of the complementation pattern of the variables, where the variables are written in a standard order, usually alphabetical. This convention assigns the value 1 to the direct form (<math>x_i</math>) and 0 to the complemented form (<math>x'_i</math>); the minterm is then <math>\sum\limits_{i=1}^n2^{i-1}\operatorname{value}(x_i)</math>. For example, minterm <math>a b c'</math> is numbered 110<sub>2</sub>&nbsp;=&nbsp;6<sub>10</sub> and denoted <math>m_6</math>.