====== Description ======
The ERROR node is a constant node that always evaluates to the internal error flag value.  It is typically used to simulate an error in a [[calculated data link]] during knowledge base development.

====== Calculus ======
The ERROR node always returns the internal error flag value.  This value is used internally to indicate networks or sections of networks that are not valid.  When a node receives an ERROR value from one of its child-nodes it also will pass the ERROR value unless the path of the child-node is inconsequential, such as an unused path in a [[switch]], [[if]], or [[SOR]] node.