Totality
Example 144
★★First we define the events, and then we create a phrase to schedule them:
"Totality"
At the time when the penumbra appears:
say "The sunlight dies away to an eerie, brownish penumbra."
At the time when the eclipse begins:
say "The moon passes across the disc of the sun, plunging the world into darkness.";
now the Chamber is dark.
At the time when the eclipse ends:
say "The moon passes away from the sun, and a gloomy penumbral light returns.";
now the Chamber is lighted.
At the time when normal sunlight returns:
say "The sun shines once more bright in the sky, not to be eclipsed again on this spot for another thirty-seven years."
To schedule an eclipse for (totality - a time):
the penumbra appears at two minutes before totality;
the eclipse begins at totality;
the eclipse ends at three minutes after totality;
normal sunlight returns at five minutes after totality.
Now we make use of the new phrase:
When play begins, schedule an eclipse for 3:27 PM.
The Chamber is a room.
The time of day is 3:25 PM.
Test me with "z / z / z / z / z / z / z / z / z".
Test me with "z / z / z / z / z / z / z / z / z".
Chamber
>(Testing.)
>[1] z
Time passes.
The sunlight dies away to an eerie, brownish penumbra.
>[2] z
Time passes.
>[3] z
Time passes.
The moon passes across the disc of the sun, plunging the world into darkness.
It is now pitch dark in here!
>[4] z
Time passes.
>[5] z
Time passes.
>[6] z
Time passes.
The moon passes away from the sun, and a gloomy penumbral light returns.
Chamber
>[7] z
Time passes.
>[8] z
Time passes.
The sun shines once more bright in the sky, not to be eclipsed again on this spot for another thirty-seven years.
>[9] z
Time passes.
>(Testing.)
>[1] z
Time passes.
The sunlight dies away to an eerie, brownish penumbra.
>[2] z
Time passes.
>[3] z
Time passes.
The moon passes across the disc of the sun, plunging the world into darkness.
It is now pitch dark in here!
>[4] z
Time passes.
>[5] z
Time passes.
>[6] z
Time passes.
The moon passes away from the sun, and a gloomy penumbral light returns.
Chamber
>[7] z
Time passes.
>[8] z
Time passes.
The sun shines once more bright in the sky, not to be eclipsed again on this spot for another thirty-seven years.
>[9] z
Time passes.
We shall see much more about creating phrases later. Their advantage is that they enable a complicated sequence of operations to be given a meaningful name, and that they can be re-used many times as needed.