Boolean operators AND, OR, AND NOT can be written in lowercase or uppercase letters.
Sequentially written words is the AND operation:
wind power is the same as wind AND power
Without parentheses, the program performs operations in the following order:
1. OR, 2. W/n and PRE/n, 3. AND, 4. AND NOT.
Parentheses can be used to specify the order of execution - the program always executes the parentheses first
finland or finnish and pisa is the same as (finland or finnish) and pisa
(wind OR solar) AND (power OR energy)
(robot* w/2 hand) OR (robot* pre/3 arm)
