Function: undiff (<expr>) Returns an expression equivalent to <expr> but with all derivatives of indexed objects replaced by the noun form of the
idiff function. Its arguments would yield that indexed object if the differentiation were carried out. This is useful when it is desired to replace a differentiated indexed object with some function definition resulting in <expr> and then carry out the differentiation by saying
There are also some inexact matches for
?? undiff to see them.
(%o1) true (%i2)