I'm trying to typeset some homework that deals with set theory and in particular I'm trying to write the "model-theoretic" notion of forcing. I put model-theoretic in quotes because I don't know the proper name for it. There's the forcing relation given by $\Vdash$
(i.e. it looks like similar to ||-
), and I'm looking for the relation that looks like ||=
, i.e. kind of like the $\models$
symbol or $\vDash$
but with an extra vertical line.
The strange thing is that it looks like the AMS packages have $\nVDash$
(i.e. the negation of the symbol I'm looking for) available, but not $\VDash$
. Detexify doesn't seem to be helping me here. Are there any symbols which look like the hypothetical $\VDash$
I'm looking for (hopefully within amsmath
, amsfonts
, or amssymb
, as I usually like to cut down on the number of packages I need to install to maintain portability across machines)?
Best Answer
\models
is defined as (use\pshow\models
where\def\pshow#1{{\let\protect\show #1}}
):In a similar fashion one could define
\mmodels
:Here's a visual of the two:
Perhaps inserting
\mkern-2mu
between the two vertical rules would look a little better: