A unuran object may implement quite a couple of generation
methods. This function tests whether the method used in unr
is an (approximate) inversion method.
It returns TRUE when unr implements an inversion method
and FALSE otherwise.
## PINV is an inversion methodunr <- pinvd.new(udnorm())
unuran.is.inversion(unr)
## TDR is a rejection methodunr <- tdrd.new(udnorm())
unuran.is.inversion(unr)