A SEIRUC mathematical model for transmission dynamics of COVID-19

The paper formulates the SEIRUC model, computes R0 via the next-generation approach, proves E0 is LAS if R0<1 and unstable if R0>1, and shows E* is LAS for R0>1 under the three explicit inequalities A1–A3 expressed through Γ1,...,Γ5, all via a Routh–Hurwitz reduction using ŝ1, t̂1, d̂1 (and â1, â5) with detailed expressions for J(E*) and the quintic coefficients âk (; ; ). The candidate solution follows the same overall route: linearization, block structure, and Routh–Hurwitz. It adds some explicit manipulations for J(E0) and the 4×4 infected block polynomial. However, it misidentifies which Routh–Hurwitz quantity corresponds to condition A3 at E* (it incorrectly ties α5>0 to A3 instead of recognizing α5=δb4(R0−1)>0 when R0>1 and that A3 corresponds to d̂1>0), and it cites a Liénard–Chipart subset without checking the usual auxiliary coefficient condition. Despite this notational/logical slip, the final conditions and conclusions (E0 threshold, E* stability under A1–A3 for R0>1) agree with the paper. Overall: both are correct on results and use substantially the same Routh–Hurwitz strategy, with the model write-up needing minor corrections in the mapping of determinants and constants (; ).