Y frawddeg yw:
Equation 5 is an accounting identity
(i.e. GDP is equal to the sum of the value added of all the sectors in the
economy).
Mae merriman-webster.com yn rhoi'r diffiniad hwn o "identity": an equation that is satisfied for all values of the symbols
Mae Wikipedian dweud: an accounting identity is an equality that must be true regardless of the value of its variables,
Dwi ddim yn meddwl bod "hunaniaeth" yn gweithio.
Diolch
Siān