Variables

Most ordinary letters are accepted as variables. These may be subscripted or superscripted so long as it is understood that the variable formed is not semantically compound. For example "x_i" can be used for "x-inner" if no reference to a variable "i" is intended. For most mathematical purposes these variables are all that is needed.

Symbolic logic expressions and some definitions require some special kinds of variables shown here:

\pvar - \tvar	Sentential Variables
\ppvar -\ttvar	More Sentential Variables
\pbar - \rbar	Unary Predicate Variables
\pbarp - \rbarp	Binary Predicate Variables
\pbarpp - \rbarpp	Ternary Predicate Variables
\ubar - \wbar	Unary Function Symbol Variables
\ubarp - \wbarp	Binary Function Symbol Variables
\ubarpp - \wbarpp	Ternary Function Symbol Variables

Examples:

(\pvar \Iff \qvar \c (\pvar \c \qvar))

(x = y \c \pbar x \Iff \pbar y)

(x \in \setof t \pbar t \Iff \pbar x \and x \in \U)