How to check if a property is overridden?

[RimuruChan]

Just like these two properties.
Thanks!

[Zastai]

If you mean, how do I tell from the PropertyDefinition that it had the override keyword in the source: you look at the accessor methods (such flags are stored separately for get/set/put/...).
And for a MethodDefinition, the logic is: a) it's virtual, b) it is not marked as a new slot, or it's flagged as having a covariant return type.
(See also this code.)

If you mean: how can I tell from the PropertyDefinition that there are derived types that have such an overriding property: you can't, unless you scan all types (and nested types) for derived classes and then match up their properties.