1. A method of providing inherited connections in circuits, comprising: specifying a hierarchical arrangement for a circuit including cell instances and connectors arranged in a tree structure that includes a top-level node at a top end of the hierarchical arrangement, wherein the cell instances include electrical devices, and the connectors include wires and pins; associating one or more connectivity expressions with the connectors for identifying corresponding signal sources for the connectors, wherein each connectivity expression includes a property name for identifying a signal source and a default value for the signal source; associating one or more property-setting expressions with the cell instances, wherein each property-setting expression relates a property name to a specified connector and associates a signal source for the property name with a signal source for the specified connector; using a computer to resolve a first signal source for a first connector associated with a first connectivity expression that includes a first property name and a first default value by following a path in the hierarchical arrangement from the first connector toward the top-level node and using one or more connectivity expressions and property-setting expressions along the path to determine the first signal source; and displaying values from the path to a user including a sequence of one or more property names and corresponding property-setting expressions along the path between the first connector and the first signal source.