POSVARDEF
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Syntax
POSVARDEF symbol
Implemented in iMath since version 2.2.0 or earlier.
Explanation
Defines the symbol to be positive (and real-valued). This allows iMath to evaluate some functions immediately, e.g. absolute value.
Note that the positive, real-valued symbol is not identical with another symbol that has the same name but a different domain. To avoid confusion, always define your symbols as positive before you use them for the first time.
Example
POSVARDEF x tells iMath that x always has a positive real value and therefore abs(x) = x.