Sehlopha ke eng khopolong ea graph?
Context:Sebakeng sa thuto ea lipalo ea graph, sehlopha ke karolo ea li-vertices tsa graph e sa laoloang e le hore li-vertices tsohle tse peli tse arohaneng sehlopheng li haufi. Ka mantsoe a mang, sehlopha sa graph G ke subgraph e hlahisitsoeng ea G e feletseng. Li-clique ke e 'ngoe ea likhopolo tsa motheo tsa khopolo ea graph' me li sebelisoa mathateng a mang a mangata a lipalo le meaho ea li-graph. Li-clique le tsona li 'nile tsa ithutoa ho saense ea k'homphieutha: mosebetsi oa ho fumana hore na ho na le sehlopha sa boholo bo fanoeng ka graph (bothata ba sehlopha) ke NP-e phethehileng, empa ho sa tsotellehe phello ena e thata, ho 'nile ha ithutoa mekhoa e mengata ea ho fumana lihlopha.  Le hoja thuto ea subgraphs e feletseng e khutlela bonyane ho graph-theoretic reformulation ea Ramsey theory ea Erdős & Szekeres (1935), lentsoe clique le tsoa ho Luce & Perry (1949), ba sebelisitseng li-subgraphs tse feletseng marang-rang a sechaba ho etsa mohlala oa lihlopha tsa batho; ke hore, lihlopha tsa batho bao bohle ba tsebanang. Li-clique li na le mekhoa e meng e mengata ea ho sebelisoa litabeng tsa saense'me haholo-holo litabeng tsa boitsebiso ba lintho tse phelang.
Ka graph khopolo, e clique ke karoloana ea vertices ea graph undirected joalo hore mong le e mong tse peli tse fapaneng vertices ka clique ba haufi.