Mini-W 1 has just been doing her maths homework. (That's math to all WARTE followers in North America and numeracy for all British readers under the age of 25).
Imagine a train which starts at a town called Noughton. The stations on the northern stretch of its route range from 1 to 20. The stations to the south are numbered from -1 to -20. On Tuesday it stops at every third station. On Wednesday it stops at every fourth station. And so on and so forth. Mini-W is then asked whether a range of statements are always true, sometimes true or never true.
I've no idea of the correct answers. But one thing's for certain. I wouldn't want to be a commuter on this particular line. Imagine that job interview:
"Well, I wouldn't be able to work on Fridays, I'm afraid. Minus Three station is closed that day and the bus from Minus Two is only doing alternate even numbers."