TY - JOUR N2 - A planar (upper) semimodular lattice L is slim if the five-element nondistributive modular lattice M3 does not occur among its sublattices. (Planar lattices are finite by definition.) Slim rectangular lattices as particular slim planar semimodular lattices were defined by G. Grätzer and E. Knapp in 2007. In 2009, they also proved that the congruence lattices of slim planar semimodular lattices with at least three elements are the same as those of slim rectangular lattices. In order to provide an effective tool for studying these congruence lattices, we introduce the concept of lamps of slim rectangular lattices and prove several of their properties. Lamps and several tools based on them allow us to prove in a new and easy way that the congruence lattices of slim planar semimodular lattices satisfy the two previously known properties. Also, we use lamps to prove that these congruence lattices satisfy four new properties including the Two-pendant Four-crown Property and the Forbidden Marriage Property. IS - 3-4 N1 - Bibliogr.: p. 412-413. ; ill. ; összefoglalás angol nyelven Y1 - 2021/// SN - 2064-8316 CY - Szeged SP - 381 KW - Matematika KW - Algebra A1 - Czédli Gábor ID - acta75847 JF - Acta scientiarum mathematicarum UR - http://acta.bibl.u-szeged.hu/75847/ VL - 87 TI - Lamps in slim rectangular planar semimodular lattices EP - 413 AV - restricted ER -