In the doc we can find symbols associated to specific toolboxes (e.g. heat_T), but is there a list of all the default symbols available in Feel ? For instance x, y, t...

In particular, can we access the dimension of the case in expression ? For instance, I'm trying to make one looking like :

"{0,0}*(dim==2) + {0,0,0}*(dim==3):dim"

which is equals to {0,0} when we run a 2D case, and {0,0,0} for 3D.