e/Additively indecomposable ordinal

Information
has gloss	eng: In set theory, a branch of mathematics, an additively indecomposable ordinal α is any ordinal number that is not 0 such that for any \beta,\gamma<\alpha, we have \beta+\gamma<\alpha. The set of additively indecomposable ordinals is denoted \mathbbH}.
lexicalization	eng: additively indecomposable ordinal
instance of	(noun) the number designating place in an ordered sequence ordinal number, no., ordinal