TY - GEN A1 - Yserentant, Harry T1 - Two Preconditioners Based on the Multi-Level Splitting of Finite Element Spaces. N2 - The hierarchical basis preconditioner and the recent preconditioner of BRAMBLE, PASCIAK and XU are derived and analyzed within a joint framework. This discussion elucidates the close relationship between both methods. Special care is devoted to highly nonuniform meshes; our theory is based exclusively on local properties like the shape regularity of the finite elements. T3 - ZIB-Report - SC-89-09 Y1 - 1989 UR - https://opus4.kobv.de/opus4-zib/frontdoor/index/index/docId/27 UR - https://nbn-resolving.org/urn:nbn:de:0297-zib-274 ER -