In the following example, an alias for stock is not required:

If a rule uses multiple topics, you must use an alias. You must specify an alias for the first topic, such as

s

for stock which is a stock event. Specify a second unique alias for the second topic, such as n for news which is a news event.

You can then use these aliases to identify the topic for which you want to evaluate a particular property. For example, in the following rule,

s.symbol

indicates that you want to evaluate the symbol property of the stock event. Also,

n.headline

indicates that you want to evaluate the headline property of the News event.