Cleverness When It Counts - Lauren Ipsum: A Story About Computer Science and Other Improbable Things - page 72

to a semantic turnstile with two guards, just like in Symbol. The guards seemed to be in the
middle of an argument.
“. . . that makes no sense, Anton!”
“It makes perfect sense, Basil. If you only—”
“Excuse me,” said Laurie. “I'd like to pass through.”
“Sorry, miss. For that, you must have a Pass signed by the Junior Officer of the Watch—”
began Anton.
“—and countersigned by the Senior Officer of the Watch,” Basil finished.
“Who are they?” she asked.
“We are.”
“Oh, good.”
“Lieutenant Basil is the Junior Officer of the Watch, and I am the Senior Officer of the
Watch—” said Anton.
“—but only on even-numbered days,” said Basil. “On odd-numbered days, I'm the Senior
Officer and Lieutenant Anton is the Junior.”
“What day is it today?”
“That's what we were discussing before you interrupted,” Anton said. “Yesterday was the
Thirtieth of Pentember. I think we all agree that thirty is an even number, and so I was the
Senior Officer.”
“That means today is the Zeroth of Hectember,” said Basil.
The Zeroth of . . . ? Well, everything has to start somewhere , Laurie thought. “So Anton
should be Junior today, and Basil should be Senior, right?”
“It's not as simple as that, miss!” said Anton.
“There is the question of whether zero is even or odd,” said Basil.
“Oh.” Laurie had never thought of zero that way. Now she was curious. “So which is it?
Even or odd?”
“Zero is even!” said Anton. “It evenly divides by two. Zero divided by two is zero.”
“That doesn't prove a thing,” said Basil. “Zero divided by any number is zero. More to the
point, if zero is even, then Anton would have two days in a row as Senior Officer, and I
won't stand for that!”