  We provide a development that unifies, simplifies and extends considerably a
number of minimax results in the restricted parameter space literature. Various
applications follow, such as that of estimating location or scale parameters
under a lower (or upper) bound restriction, location parameter vectors
restricted to a polyhedral cone, scale parameters subject to restricted ratios
or products, linear combinations of restricted location parameters, location
parameters bounded to an interval with unknown scale, quantiles for
location-scale families with parametric restrictions and restricted covariance
matrices.
