hálfgrúpa

Icelandic

Etymology

From hálf- (“half-”) +‎ grúpa (“group”).

Noun

hálfgrúpa f (genitive singular hálfgrúpu, nominative plural hálfgrúpur)

1. (mathematics) a semigroup; (any set for which there is a binary operation that is both closed and associative)

Declension

Declension of hálfgrúpa (feminine, based on grúpa)

	singular		plural
	indefinite	definite	indefinite	definite
nominative	hálfgrúpa	hálfgrúpan	hálfgrúpur	hálfgrúpurnar
accusative	hálfgrúpu	hálfgrúpuna	hálfgrúpur	hálfgrúpurnar
dative	hálfgrúpu	hálfgrúpunni	hálfgrúpum	hálfgrúpunum
genitive	hálfgrúpu	hálfgrúpunnar	hálfgrúpna	hálfgrúpnanna

Derived terms

• styttin hálfgrúpa (“cancellation semigroup”)
• hálfgrúpumótun (“semigroup homomorphism”)
• hálfgrúpa með hlutleysu (“semigroup with identity element, monoid”)