FA-40433 / Heap invariants / Member archive

Interval heap maximum is the root upper endpoint even with a singleton tail · case 03

The bounded interval endpoints certificate reports an incorrect maximum.

Member previewVariant 3 · 3 implementations · 7 checks per implementation

Case contract

An interval heap stores ordered pairs [lo,hi] except the last node may be singleton [x]. Report reversed intervals, low-end heap violations, high-end heap violations treating singleton as both endpoints, global minimum, global maximum, and member count.

Why this case matters

This isolates an internal heap representation or priority-structure invariant using deterministic finite records.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
regression certificate 3	`{"high_order": [], "low_order": [], "maximum": 3, "members": 5, "minimum": 1, "reversed": []}`	`{"high_order": [], "low_order": [], "maximum": 9, "members": 5, "minimum": 1, "reversed": []}`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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