noun
combinatorics
Mathematical field studying counting, arrangement, and combination of discrete structures.
組み合わせ論は離散数学の一分野です。
Combinatorics is a branch of discrete mathematics.
Standard modern spelling with okurigana.
Variant spelling without okurigana; seen in some technical contexts.
Discrete mathematics is the broader field; combinatorics is a core subfield within it.
Compound of 組み合わせ (combination) + 論 (theory, discourse).