(2) The point can here be brought out as follows.
  Take φa, & φA: , where & ask what is meant by saying “There is a thing in φa, & a complex in φA”?
  (1) means: (∃x). φx . x = a


  (2) means φ [aRb] = ψa . ψb . aRb Def.

x A = aRb Def.


  We then get (∃x,y,(ξRη) . φx . φy . xRy


(∃x,ψξ). φA = ψx . φx