Compound Cycle Processor
Graph Transformer
Comment Preprocessor
Edge And Layer Constraint Edge Reverser

Layer Constraint Processor
Hierarchical Port Constraint Processor
Compound Dummy Edge Remover
Long Edge Splitter
Port Side Processor
Label Dummy Switcher
Inverted Port Processor
Self Loop Processor
Port List Sorter
North South Port Preprocessor

Subgraph Ordering Processor
In Layer Constraint Processor
Hyperedge Dummy Merger
Label Side Selector
Label And Node Size Processor
Node Margin Calculator
Compound Side Processor

Layer Size and Graph Height Calculator
Hierarchical Port Dummy Size Processor
Hierarchical Port Position Processor

Comment Postprocessor
Hypernode Processor
Hierarchical Port Orthogonal Edge Router
Long Edge Joiner
North South Port Postprocessor
Label Dummy Remover
Reversed Edge Restorer
Compound Graph Restorer
Graph Transformer
End Label Processor

• The graph is layered.
• Nodes to be placed in the first layer only have outgoing edges.
• Nodes to be placed in the last layer only have incoming edges.

• Nodes with layer constraints have been placed in the appropriate layers.

• ConstrainedHierarchicalPortProcessor

• Layerers should usually include a dependency on this processor, unless they already adhere to layer constraints themselves.
• The LayerConstraintEdgeReverser ensures that this processor's preconditions are met. Thus, layerers should also include a dependency on that processor.

• If FIRST_SEPARATE nodes exist, they must all be present in the first layer. In that case all FIRST nodes must be located in the next layer, otherwise in the first layer. Analog for LAST_SEPARATE and LAST.