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Skew meld traversal follows swapped structure rather than identifier ordering · case 05

The bounded skew meld step certificate reports an incorrect preorder children.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

A skew meld unwind chooses the smaller root, recursively melds its old right subtree with the other heap, and unconditionally swaps children. Record supplies winner, old_left, recursive_result and sizes. Missing subtrees are None. No rank-based swap condition is part of this model.

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 4	`{"leaf": false, "new_left": 2, "new_right": 1, "preorder_children": [1, 2], "rewrites": [[2, 9], [1, 9]], "size": 9}`	`{"leaf": false, "new_left": 2, "new_right": 1, "preorder_children": [2, 1], "rewrites": [[2, 9], [1, 9]], "size": 9}`	Failed

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

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