FA-6048 / Linear algebra / Member archive

Matrix frobenius norm squared · case 03

Squaring a total introduces cancellation and cross terms.

Member previewVariant 3 · 3 implementations · 4 checks per implementation

Case contract

Integer matrix/vector entries, rectangular rows, compatible multiplication dimensions, and square matrices for determinant, trace, inverse, symmetry and characteristic-polynomial operations. Rational matrix outputs are reduced Fraction strings. Matrix frobenius norm squared. Exact operational definition: sum(x*x for row in m for x in row)

Why this case matters

Small exact fixtures expose this error without platform timing, external services, or probabilistic observations. Linear algebra results depend on the stated convention.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
fixture 1: ([[1, 2], [3, 4]],)	`100`	`30`	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.