I have been using the TeX input method a bit this week to input math
characters in a Unicode document. I have, however, encountered one
issue: lack of the \Dashv (reverse of \vDash or \models, although those
don't yield identical symbols) symbol or an equivalent that I can find.

Is there such a character in Unicode? If so, is there a way I can enter
it using the TeX input method, or via some other sufficiently simple
method?

- Michael