add_natural_viscosity_terms Interface

interface
private module subroutine add_natural_viscosity_terms(x, elements, settings, grid, background)

Type	Intent		Name
real(kind=dp),	intent(in)	::	x
type(matrix_elements_t),	intent(inout)	::	elements
type(settings_t),	intent(in)	::	settings
type(grid_t),	intent(in)	::	grid
type(background_t),	intent(in)	::	background