If the youths warm to each other, the fair can trigger complex financial negotiations about the price a young man's family must pay to a woman's parents if they are to wed.

NPR: Gypsies Flock To Bridal Fair As Parents Negotiate

It will finally bring transparency to the kinds of complex and risky transactions that helped trigger the financial crisis.

WHITEHOUSE: Signing the Wall Street Reform and Consumer Protection Act

Because of reform, the kind of complex, backroom deals that helped trigger this financial crisis will finally be brought into the light of day.

WHITEHOUSE: President Obama on Wall Street Reform Vote

Because of reform, the kinds of complex, backroom deals that helped trigger the financial crisis will finally be brought to the light of day.

WHITEHOUSE: President Obama Hails Progress on Wall Street Reform

The reasons why someone might take as drastic a step as killing himself are complex and rarely boil down to a simple trigger, experts say.

WSJ: Legal Case Strained Troubled Web Activist

Now, 30% doesn't automatically trigger precipitation icons, and a more complex algorithm decides when the company signals wet weather, with a goal of removing the wet bias.

WSJ: Some Percentages Are Just Fair-Weather Friends

Another alternative, the EIA test, which detects substances produced by the chlamydia bacteria that trigger the immune system or immune system chemicals produced in response, is less complex.

BBC: NEWS | Health | 'Instant test' for sex disease