To be allowed in the park, you must be over 21, be over 16 and have an adult with you, be under 21 and have an adult with you, or be under 21 and with a school group.
To summarize in the same order as the logic statement:
- be over 21
- be over 16 and have an adult with you
- be under 21 and have an adult with you
- be under 21 and with a school group