through to SVi=4 selects SVSHAPE3.
* Vertical-First Mode will return the current index
- (and move to the next if `vf=1`)
-* Horizontal-First Mode can be used to return all indices
+ (and move to the next state if `vf=1`)
+* Horizontal-First Mode can be used to return all indices,
+ i.e. walks through all possible states.
To obtain the full set of possible computed element
indices use `svstep RT.v,SVI,1` which will store all computed element