6. The method of claim 4 wherein said plurality of user commands includes a connect command that connects a signal net to an instance connector of an instance.
6. The method of claim 4 wherein said plurality of user commands includes a connect command that connects a signal net to an instance connector of an instance. 8. The method of claim 6 wherein said plurality of user commands includes a disconnect command that disconnects all signal nets connected to a specified instance connector of an instance.