Time evolution of semimajor axes (upper left panel), eccentricities (lower left panel), and two-body MMR and three-body Laplace angles (right panel) in a disk migration simulation of the Kepler-223 system with α = −2.586 and β = −1.966. This (α, β) combination is just below the analytic convergent outward migration zone, but the resonant chain is maintained to the end of the simulation.