, equal to two, by the addition of unity to the former
on that column). Now Operation 7 must either bring out a result equal to zero (if
); or a result greater than zero, as in the present case; and the engine follows the one or the other of the two courses just explained, contingently on the one or the other result of Operation 7. In order fully to perceive the necessity of this experimental operation, it is important to keep in mind what was pointed out, that we are not treating a perfectly isolated and independent computation, but one out of a series of antecedent and prospective computations.
Cards 8, 9, 10 produce
. In Operation 9 we see an example of an upper index which again becomes a value after having passed front preceding values to zero.
has successively been