Examples:

XSPEC> thl 6.4,.34,7.1,20.,,,.015    ! Calculate the expected equivalent
                                          width for a line at 6.4 keV with a
                                          fluorescent yield of 34%. The
                                          absorption edge is integrated from
                                          7.1 keV to 20. keV in 200 steps. The
                                          maximum depth is .015.

XSPEC> thleqw ,,,,,,100              ! As before, but with 100 steps

XSPEC> thleqw                        ! As before.

Don't forget to read the response file in again if you want to do further work on the same data.