semilattice 3 semigroup 2 05C25 1 06B10,11A99 1 06B99 1 08A05 1 20E99 1 20M05 1 20M15 1 20M20 1 22A05 1 22A15 1 22A26; 20M18 1 Semigroup presentations 1 \(H\)-closed 1 absolutely \(H\)-closed 1 closure 1 co-maximal 1 commutative dimonoid 1 convolution 1 cover 1 dimonoid with a commutative operation 1 idempotent monoids 1 inverse semigroup 1 inverse subsemigroup 1 lattice 1 lattice of normal subgroups 1 multiplicative 1 order-preserving transformation 1 orientation-preserving transformation 1