This package extends the ifthen package by implementing new commands to go within the first argument of \ifthenelse: to test whether a string is void or not, if a command is defined or equivalent to another. The package also enables use of complex expressions as introduced by the package calc, together with the ability of defining new commands to handle complex tests.

The package requires e-TeX features.

See also ifthen ifthenx.

The author is Josselin Noirel.