Volume 18, Issue 3 Paweł Wójcik Characterizations of inner product spaces by inequalities involving semi-inner product Downloads Abstract PDF Full article PDF DOI { copied = true; setTimeout(() => copied = false, 2000) })" :aria-label="copied ? 'DOI copied' : 'Copy DOI'" :title="copied ? 'Copied' : 'Copy DOI'" > Find all available articles from these authors Paweł Wójcik Find more articles with the same keywords semi-inner product characterization of inner product spaces inequality projection smoothness norm derivative Find more articles with the same subject classes 46C15 46C50 46B20 39B62