Same as in the getPreviousLocalSolutions().

for flexibility in coupling.

for the staggered scheme.

about getting the local solutions of an element.

Clang format run on near-the-header lines.

Happy New Year

 from the two classes of coupled term.

[Coupling] Changed the members of the coupled term,

 which only contains the solutions of the coupled equations.

added more documentations about the staggered scheme

coupled terms.