GENERIC INTERFACE ElectricEvaluator (Atr, Erg);
  (* 
    WHERE 
      /\ TYPE Atr.T
      /\ Erg = Energy(Atr) *)

TYPE T <: Erg.T;

PROCEDURE New(
    READONLY q: ARRAY OF Atr.T; (* Charge positions *)
    READONLY w: ARRAY OF REAL;              (* Charge magnitudes *)
    radius: LONGREAL;
  ): T;
  (*
    Returns an evaluator "e" that treats each attribute vector "q[j]" 
    as the position of a fuzzy electric charge of magniture "w[j]"
    and approximate extent "radius".  The value of "e(p)" is then
    the electric potential of a unitary negative electric charge 
    at point "p". *)

END ElectricEvaluator.