15.1. Understanding Boolean Functions

Boolean functions aren't a distinct group like Text or Number functions. Nor is Section 7.5.1.3 a choice in the "Calculation Result is" pop-up menu. It's the result of a calculation that makes it Boolean. Regular calculations return results like 3.14 or 753 or "Dread Pirate Roberts." Boolean results refer to the theory of logic, and can always be reduced to either "true" or "false," "yes" or "no," "not empty" or "empty." Conditional Formatting calculations are always Boolean, since FileMaker needs to know if a particular condition is true before it can decide when to apply the formatting you set up. You can learn a lot about Boolean calculations by exploring the Conditional Formatting dialog box (Figure 15-1). See the box on Separating Formatting from Data for more on using Conditional Formatting.

The Boolean world has no shades of gray, no "maybe," and no glasses that are half full. For example, these statements are true, as most any schoolchild can tell you: