$ jacobi run elastic_j2.f
Compiling with gfortran -O2 -Wall...
Running 12 physics tests
✓ A Uniaxial C₁₁₁₁ err: 0.021%
✓ B Lateral C₁₁₂₂ err: 0.008%
✓ C Shear G err: 0.000%
✓ D Bulk K err: 0.031%
✓ E J2 neutrality 20/20 steps
✓ F Yield onset step 8 ✓
✓ G Elastic unload C₁₁₁₁ ok
✗ K Incompressibility 1.2e‑6 > tol
✓ L Yield return err: 0.04%
✓ H Zero increment |dσ|=1e‑14
✗ I DDSDDE FD 3.4% > 1% tol
✓ J DDSDDE symmetry |C-Cᵀ|=8e‑15
10 passed · 2 failed
K: tr(dεp) = 1.2e-6 > tol — isochoric
flow violation. Check NHAT...
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