FA-67784 / Elevator dispatch scheduling / Member archive

Hall button registration and cancellation: terminal button validity · case 04

Non-existent terminal buttons register calls that no car will answer.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Hall buttons exist on floors 0..floors-1, except no up button at the top floor and no down button at the bottom floor; other presses are ignored. A registered call lights. A car arriving at a floor serves calls matching its direction; an idle car or a car arriving at a terminal floor (where it must reverse) serves both directions. Log lit/ignored and served:<dirs> (sorted), and list pending calls sorted.

Why this case matters

Lift group controllers make these decisions many times per minute; a wrong answer strands passengers, wastes trips or overrides a safety rule.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: down button at the lobby	`{"log": ["lit", "lit"], "pending": [[0, "down"], [0, "up"]]}`	`{"log": ["ignored", "lit"], "pending": [[0, "up"]]}`	Failed

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