FA-15462 / Numerics / Member archive
Exact ldl decomposition: lower factor diagonal divisor · case 02
The exact exact ldl decomposition result violates the stated contract at lower factor diagonal divisor.
Case contract
Input symmetric positive definite integer matrix; return unit lower L and diagonal D as rational pairs such that A=L*D*Ltranspose.
Why this case matters
Exact discrete arithmetic with observable algorithmic state; no floating point approximation is used.
One recorded failure
Sample boundary fixtureThis sample comes from the broken implementation of a controlled reproducer.
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| explicit oracle 0 | [[[[1, 1], [0, 1], [0, 1]], [[2, 11], [1, 1], [0, 1]], [[6, 11], [27, 77], [1, 1]]], [[11, 1], [150, 11], [264177, 65219]]] | [[[[1, 1], [0, 1], [0, 1]], [[2, 11], [1, 1], [0, 1]], [[6, 11], [9, 25], [1, 1]]], [[11, 1], [150, 11], [99, 25]]] | Failed |
MEMBER ARCHIVE
The complete case is available to members.
This record includes three runnable implementations, regression fixtures, execution results, and source hashes.
Member access is invitation-based. Sign in with your invited account to inspect the sources.
Sign in to the archive ↗