EntityQ1876526· pop 18· linked from 64 articlesessential singularitySign in to saveisolated singularity that is neither removable nor a poleConnectionspoleEntityInternational Standard Book NumberEntitycomplex numberEntityfunctionEntitydigital object identifierEntityInternational Standard Serial NumberEntityabsolute valueEntitycomplex analysisEntityQ118398EntityRiemann zeta functionEntitycomplex planeEntityholomorphic functionEntityLars AhlforsEntityopen setEntityrational functionEntityneighborhoodEntityStephen WolframEntityanalytic functionEntitymeromorphic functionEntityLaurent seriesEntityCategoriesComplex analysis