• Returns intersection of given sets
• Sets are lists composed of any kind of data
• Given sets may be specified either by a variable containing two or more lists or by sets named within parentheses

Example:
  (INTERSECTION-OF ((COMMON-ORTHOLOGS-OF (Npun A7120))
                    (COMMON-ORTHOLOGS-OF (Npun S6803))))
  :: 3894 common orthologs found
     2131 common orthologs found
     1945 elements in INTERSECTION
     (#$Npun.p-NpR2542 #$Npun.p-NpF3886 #$Npun.p-NpR1946 #$Npun.p-NpR2772
      #$Npun.p-NpF4228 #$Npun.p-NpF0021 #$Npun.p-NpF0114 #$Npun.p-NpF1033
      ...

      [Result is a list of proteins found in each of N. punctiforme, Anabaena PCC7120,
        and Synechocystis PCC6803]