public static SCode Make(Primitive2 rator, LexicalVariable rand0, SCode rand1)
 {
     return
         ((rand0 is Argument) ? PrimitiveIsObjectEqA.Make(rator, (Argument)rand0, rand1)
         : (rand0 is LexicalVariable1) ? PrimitiveIsObjectEqL1.Make(rator, (LexicalVariable1)rand0, rand1)
         : (rand1 is LexicalVariable) ? Unimplemented()
         : (rand1 is Quotation) ? PrimitiveIsObjectEqLQ.Make(rator, rand0, (Quotation)rand1)
         : new PrimitiveIsObjectEqL(rator, rand0, rand1));
 }