The common methods for simplifying the logic function are two:one formula method, another figure method.

逻辑函数常用的化简方法有两种，即公式法和图形法。

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Before the advent of computers and charting software, pit traders and market makers used this method to figure out where the markets might be heading.

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The second method is to take a figure close to where the floating currency is presently trading.

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The Bank of Scotland Labour Market barometer is a method of giving a single figure snapshot of labour market conditions.

BBC: Scotland