non- + identity
nonidentity (plural nonidentities)
- Difference, distinction; failure to be identical.
1993, Ordway Hilton, Scientific Examination of Questioned Documents[1], →ISBN, page 395:No scientific examiner would select only chance variations to establish nonidentity of two specimens when the fundamental points of identification stamp them as originating at a single source.
- (mathematics) An operator which modifies its operand, and which therefore is not the identity.
1995, Thomas A. Whitelaw, Introduction to Abstract Algebra[2], →ISBN, page 99:Moreover, in a group of prime order p, every non-identity element (i.e. every element other than 1) has period p.