NSTD.8:5.3 - Worked learning route: homotopy explanation

LearningNarrativeRoute@HomotopyIntro:
  learnerUse: learner distinguishes intuitive deformation picture from formal definition and proof boundary
  sourceSpineRefs:
    - topological space
    - path
    - homotopy relation under constraints
    - invariant
    - example and counterexample
    - proof-status return
  learningStepOrder:
    - image cue
    - constraint marker
    - formal definition return
    - example
    - counterexample
    - reconstruction task
  reconstructionTasks:
    - mark where analogy stops
    - state which deformations are not allowed
    - return one claim to formal source
  engagementBoundaryRef: vivid image cannot replace definition
  evaluationRouteRef: `NSTD.6` rows for ordering, language-state precision, and source return

If learners can retell the loop picture but cannot state the required constraint, repair the connection to the definition. A suitable example, counterexample or worked comparison may supply that repair.