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+[[Property:uuid|88764AFC-7DC5-4547-8B8C-4C0A489B0620]]
+[[Property:weight|0]]
+[[Property:title|Types]]
+= Types =
+
+== Common ancestor type ==
+
+A *common ancestor type* is a type computed for a list of types using the following algorithm:
+
+1. Temporary ignore whether any types are detachable or separate.
+2. Add a type `NONE` to the list of types (this makes sure the list is never empty).
+3. If there is a type in the list to which all other types conform, remember it as T.
+4. Otherwise, use `ANY` for T.
+5. If there is a detachable or separate type in the list, use the corresponding detachable and/or separate version of type T.
+