Not an error to reference global ground in ddx() call
I have a line in my Verilog-A code (bsimsoi.va) that says
B4soigm = B4soitype * ddx(Ids, V(gi));
V(gi) implicitly refers to ground, measuring the node voltage rather than a branch voltage. However, ddx() requires use of a node voltage, rather than a branch voltage. Thus, this should not be an error.