2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/225500We exhibit a weight-preserving bijection between semi-standard Young tableaux and semi-skyline augmented fillings to provide a combinatorial proof that the Schur functions decompose into nonsymmetric functions indexed by compositions. The insertion procedure involved in the proof leads to an analogue of the Robinson-Schensted-Knuth Algorithm for semi-skyline augmented fillings. This procedure commutes with the RSK algorithm, and therefore retains many of its properties.24 pages; restructured; see journal for comment on connections to Demazure charactersCombinatorics05E05; 05E10text