half-open interval

[haf-oh-puh n, hahf-]

noun Mathematics.

a set of numbers between two given numbers but including only one endpoint.

Also called half-closed interval [haf-klohzd, hahf-] /ˈhæfˌkloʊzd, ˈhɑf-/
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019