1*46696af2SBarry Smith# Dual Spaces (PetscDualSpace) 2*46696af2SBarry Smith 3*46696af2SBarry SmithThe `PetscDualSpace` class encapsulates a function space that is the dual (<a href="https://en.wikipedia.org/wiki/Dual_space" target=_blank>https://en.wikipedia.org/wiki/Dual_space</a>) of a `PetscSpace` class. 4*46696af2SBarry Smith 5