From QB64.org wiki
The < condition symbol denotes that a value must be less than another value for the condition to be True.
Example usage: IF x < 320 THEN PRINT "Left of screen"
- Statements will evaluate as True or -1 when the first value is less or False or 0 when the first value is equal or greater.
- More than one < symbol in a numerical statement will create a Boolean evaluation of the ensuing numerical value.