sum!(
other : NTP
) : SAME ;
-- This iter feature yields the sum of all previous values of other.
-- Note that other is re-evaluated on each re-entry of the iter. Dependent
-- on the value provided, this iter may therefore produce a non-representable
-- value which shall cause an exception to be raised.
product!(
other : NTP
) : SAME ;
-- This iter feature yields the product of all previous values of
-- other. Note that other is re-evaluated on each re-entry of the iter.
-- Dependent on the value provided, this iter may therefore produce a
-- non-representable value which shall cause an exception to be raised.