ABSTRACT
In Sections 6, 7 and 8 the examples considered all involved nested spaces and inherited forms. In this section we describe a practical setting in which the nonnested space, noninherited form multigrid theory of Section 4 may be profitably employed. Consider, on a planar domain Ω, the biharmonic Dirichlet problem. () Δ 2 u = f u = ∂ u ∂ n = 0 on ∂ Ω , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203746332/608738f3-7c7a-4b45-bdd9-ce6f43c0b870/content/eq907.tif"/>
