Stations are where work happens. Layers are the kinds of engineering that make it work. All seven run under all six stations, so a change to one layer is felt across the whole line.
PLANEXPLOREDESIGNBUILDREVIEWMAINTAIN01Prompt
PLANEXPLOREDESIGNBUILDREVIEWMAINTAIN02Context
PLANEXPLOREDESIGNBUILDREVIEWMAINTAIN03Knowledge
PLANEXPLOREDESIGNBUILDREVIEWMAINTAIN04Harness
PLANEXPLOREDESIGNBUILDREVIEWMAINTAIN05Loop
PLANEXPLOREDESIGNBUILDREVIEWMAINTAIN06Tools
PLANEXPLOREDESIGNBUILDREVIEWMAINTAIN07Evaluation
Public copy calls these “the underground”. “Layer” means only these seven.