tdiff_distributions     Distribution Functions for Approximated
                        t-Difference
validate_approximation
                        Validate Welch-Satterthwaite Approximation
ws_tdiff_equal_params   Equal Parameters Special Case
ws_tdiff_multivariate_general
                        Welch-Satterthwaite Approximation for General
                        Multivariate t-Differences
ws_tdiff_multivariate_independent
                        Welch-Satterthwaite Approximation for
                        Multivariate t-Differences (Independent)
ws_tdiff_univariate     Welch-Satterthwaite Approximation for
                        Univariate t-Differences
