1submodule (parent:container) helper 2 implicit none 3 4contains 5 6 module function parent_distance(pa, pb) result(dist) 7 type(parent_type), intent(in) :: pa, pb 8 real :: dist 9 10 dist = sqrt(parent_weight(pa) + parent_weight(pb)) 11 end function parent_distance 12 13end submodule helper 14