Add proposition and then support it in Sequences of coincedence

[LeeCampbell]

need reason why we care. Create a proposition and support it. -->

• Number of requests while database is down
• When person loggedin to a chat, get their tweets
• Notify when a stock price moves by more than 2% in 4 hrs
• When FX rates move by more than X in Y time, notify of trades booked in that currency
• Album sales by artist, by location, the day after concert.
• Presidential Election
• Google searches for Marathon during Marathon races
• Tweets tagged #Euro given a price change of x over a period of time y.
• Hmmm look to Rx forums for some good examples...

Complex query may require more than just composition of sequences and operators.

Interrogate one sequence based on the activity in another sequence