【计】 hierarchical set
classify; grade
【计】 outline
【化】 classification; fractionation
【经】 grading; scale
gather; troop together; aggregate; assemble; concourse; convene; muster
rendezvous; congregation; concentration
【计】 disjoint set
【医】 aggregate; aggregation; agmen; agmina; convergence
【经】 assembly