2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/171476Combining the "method of restriction equations" of Rimányi et al. with the techniques of symmetric functions, we establish the Schur function expansions of the Thom polynomials for the Morin singularities $A_3: ({\bf C}^{\bullet},0)\to ({\bf C}^{\bullet + k},0)$ for any nonnegative integer $k$.18 pages; Preprint RIMS Kyoto No.1638 (2008)Algebraic Geometry05E05, 14N10, 57R45text