get_partial_duvenaud_update_weight Function

  function get_partial_duvenaud_update_weight(this, upstream_grad) result(output)
    !! Gradient of duvenaud_update with respect to packed weights.
    implicit none

    ! Arguments
    class(array_type), intent(inout) :: this
    !! Forward result node containing saved operands
    type(array_type), intent(in) :: upstream_grad
    !! Upstream gradient tensor
    type(array_type) :: output
    !! Gradient tensor for left operand (weights)

    ! Local variables
    logical :: right_is_temporary_local
    !! Saved temporary-ownership flag for right operand
    type(array_type), pointer :: ptr
    !! Intermediate gradient tensor pointer

    right_is_temporary_local = this%right_operand%is_temporary
    this%right_operand%is_temporary = .false.
    ptr => duvenaud_update( this%right_operand, upstream_grad, &
         this%indices, this%left_operand%indices(1), this%left_operand%indices(2) )
    this%right_operand%is_temporary = right_is_temporary_local
    call output%assign_and_deallocate_source(ptr)

  end function get_partial_duvenaud_update_weight