There is no operation that connects this variable to the independent variables.
yes_connected
There is one or more operations that connects this variable to the independent variables.
sum_connected
There is only one parrent operation that connects this variable to the independent variables and it is one of the following: AddvvOp, AddpvOp, SubpvOp, SubvpOp, or SubvvOp.
csum_connected
Satisfies sum_connected and in addition the parrent operation is one of the following: AddvvOp, AddpvOp, SubpvOp, SubvpOp, or SubvvOp.