Naming the pairs...

We could go old-fashioned:

 

Factor and Agent

 

"Energy and persistence conquer all things." -- Benjamin Franklin 

Toby Considine
TC9, Inc

OASIS Technical Advisory Board
TC Chair: oBIX & WS-Calendar

TC Editor: EMIX, EnergyInterop

  

Email: 

Phone: (919)619-2104

http://www.tcnine.com/

blog: www.NewDaedalus.com