Grid sections

For a given i, a dimensional grid section of an N-grid Q via a member m of dimension Di is the subset

Qm = m Ä DÁ\i

of Q regarded as a (N-1)-grid.

For a given multiindex I of length k, a general grid section of Q via a point m of DI is the subset

Qm = m Ä DÁ\I

of Q regarded as a (N-k)-grid.