Parallelogram Norm ∗
نویسندگان
چکیده
Replacing the triangle inequality by ‖x + y‖ ≤ 2(‖x‖ + ‖y‖) in the definition of norm we obtain the notion of parallelogram norm. We establish that every parallelogram norm is a norm in the usual sense. ∗2000 Mathematics Subject Classification. Primary 46B20; secondary 46C05.
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