FA-39959 / Heap invariants / Member archive

Pairing degree counts only the first child pointer · case 04

The bounded pairing siblings certificate reports an incorrect degrees.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Pairing-tree certificate nodes are [key,parent,first_child,next_sibling,previous]. Missing links are -1. Previous denotes parent for first child, prior sibling otherwise. Report first-child backlinks, sibling-parent disagreements, previous-link disagreements, root sibling violations, direct heap-order violations, and child-chain degrees (stop on cycles).

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	`{"child_order": [], "degrees": [1, 0, 0], "first_previous": [], "root_links": [], "sibling_parent": [], "sibling_previous": []}`	`{"child_order": [], "degrees": [2, 0, 0], "first_previous": [], "root_links": [], "sibling_parent": [], "sibling_previous": []}`	Failed

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