What's the difference between Conditionals and Predicates
that is a good question.
Depending in the definitions, you can exclude them or not.
In my opion :
A WHERE Clause is conditional, because it decides at the end which rows are selected depending on the conditions.
For a predicate the result only can be True or False, and a WHERE clause can't return this result.
I thought about that you need predicates to decide if a row is in the result set or not, but the WHERE clause as total doesn't return True or False