Does the identity of indiscernibles principle indicate that, for example, a

Does the identity of indiscernibles principle indicate that, for example, a person with N number of hairs, who then loses a hair, is not identical to the person with N -1 number of hairs? Unless I'm mistaken the principle is basically that entities having all of their properties in common are identical entities, but is it also true that two entities not having all of their properties in common (like Bill with N hairs and Bill with N -1 hairs) are not identical? Can entities with different properties nevertheless be identical? If so, how can we determine that Bill and Sally aren't identical, since merely not having all of their properties in common does not exclude the possibility of identity?

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