EntityQ175116· pop 21· linked from 293 articlesdiscrete spaceSign in to savetopological space whose every subset is both open and closedConnectionsmetric spaceEntitycountable setEntitycomplete metric spaceEntitymetrizable spaceEntitysubsetEntityuniform continuityEntityLipschitz functionEntitysubspace topologyEntityuniform spaceEntitymetric mapEntityIntrinsic metricEntityDelone setEntityInternational Standard Book NumberEntitynatural numberEntityintegerEntitytopologyEntitysetEntityirrational numberEntitygroupEntityempty setEntityCategoriesGeneral topologyMetric spacesTopological spaces