var n=3, x=1.0, a=5, z="zoo";
self.vars; --> L(L("a",5),L("n",3),L("x",1),L("z","zoo"))
sum:=self.vars.reduce(fcn(p,[(nm,v)],r){
   if((1).isType(v)){r.inc();p+v;} else p},0,num:=Ref(0));
println("Num int vars = ",num.value,". Sum = ",sum);