module cdoubint	{ # double integration
  use causint
  use chain_mod
  real, dimension (nx), allocatable :: tmp
#% _init (nx)
    integer :: nx
#% _lop (x, y)
    if (adj)
       call normal (causint_lop, .true., y, x, tmp)
    else
       call normal (causint_lop, .true., x, y, tmp)
}