math forumulae
When your hotel is in Cambridge
When your hotel is in Cambridge
When your hotel is in Cambridge
When your hotel is in Cambridge
When your hotel is in Cambridge

...you might expect to see in the hotel a bedspread like this. Kate told me immediately that she could define each one. Of course I felt like a mental mouse.

So here's a challenge: What do these formulae mean? (And John and Rad, you can answer only one -- give everyone else a chance!)

Quite an auspicious way to kick off a week of Drupal, I'd say.