CRITERIA

 In Empire, criteria means a specific syntax used to define a set
of land sectors.  Specifically, the sector criteria is enclosed
in parenthesis and includes keywords for qualifying sectors.

(  [] ... [] )

   Where:  =   
             = A[rtillery] / B[ombers] / C[ivilians]
                        D[esignation] / E[xplosives] / EF[ficiency]
                        F[ighters] / M[ilitary] / N[ation]
                        O[re] / P[roduction] / R[egion] / S[ample]
            = one of =, >, < or # (not equal to)
               = For keywords A,C,E,EF,M,N,O,P and S this is
                          a numeric literal.
                        For DESIGNATION this is A,C,D,E,F,M,P,R,S,
                          T,U,W,^,+ or (
                        For REGION this is x1,y1,x2,y2

  Examples:
    TROOP (D=M R=3,3,7,6)
    SPY (N=14 D=C) (N=14 D=+) 
    DESIGNATE (D=R S>9)

Although not stated in the Example, the first one means to run the "TROOP" command (i.e. display the status) of the land spaces that are Designated as Mines and are bordered by X1,Y1, X2,Y2 coordinates of spaces X=3, Y=3, X=7, Y=6.

The second example means to "SPY" adjoining land spaces that are for Nation #14 and are Designated as Capitols or Airports(+).

The third example means to run the "DESIGNATE" command for places that are (already) Designated Rural and have an ore Sample of greater than nine per cent.