Crystal Reports for Rational Application Developer Designer Guide
Boolean operators (Crystal syntax)
The Boolean operators are, in order of precedence from greatest to lowest: Not, And, Or, Xor, Eqv and Imp.
Boolean operators are typically used with comparison operators to generate conditions for control structures. Boolean operators as a group have lower precedence than the comparison operators. Thus for example, the expression 2 < 3 And 4 >= -1 is the same as (2 < 3) And (4 >= -1).