This belongs to the provisions of each textbook. Personally, except for "non", there is no difference in the priority of conjunctions and disjunctions, but brackets cannot be omitted. If conjunctions and disjunctive words appear next to each other, they must be put in brackets, such as P∧Q∨R, and they must be written as (P∧Q)∨R or P∧(Q∨R). You can look through the textbooks. The form P∧Q∨R does not exist.