Congruences in semigroups are similar to normal subgroups in groups and ideals in rings.By congruencs, one can thoroughly obtain characterizations of E-inversive semigroups. 摘要半群的同余類(lèi)似于群中的正規子群或環(huán)中的理想,旨在對代數系統進(jìn)行分類(lèi),以期得到關(guān)于半群的細致刻畫(huà)。