BinaryDecisionDiagramVisitor

Implements the Visitor pattern over a BinaryDecisionDiagram to its hierarchy, which only includes instances of BinaryDecisionDiagram.Terminal and BinaryDecisionDiagram.Variable. This abstraction is the method of choice to explore the internal structure of a BDD, dispatched through BinaryDecisionDiagram.accept rather than by checking BinaryDecisionDiagram.isTerminal/BinaryDecisionDiagram.isVariable and casting manually. All BDD operators and utilities in this module (e.g. expansion, apply, any, map) are themselves implemented as internal visitors.