Distinguish between lvals and rvals in captured closure environment

public class Hello {
    public static def main(args: Array[String]) {
	TestValInitUsingAt.testVal();
	TestValInitUsingAt.testVar();
    }
}
class TestValInitUsingAt { 
    static def testVal() {
        val x_tmp1:Int;
        val p = here;
        at (p.next())
          at (p)
            x_tmp1 = 2;
        val x = x_tmp1;
	Console.OUT.println("should be 2: "+x);
        at (p.next())
          at (p)
            Console.OUT.println("should be 2: "+x_tmp1);
    }
    static def testVar() {
        var x_tmp2:Int;
        val p = here;
        at (p.next())
          at (p)
            x_tmp2 = 2;
        val x = x_tmp2;
	Console.OUT.println("should be 2: "+x);
        x_tmp2 = 100;
        at (p.next()) {
          at (p) {
	    Console.OUT.println("should be 100: "+x_tmp2);
            x_tmp2 = 200;
	    Console.OUT.println("should be 200: "+x_tmp2);
          }
        }
	Console.OUT.println("should be 200: "+x_tmp2);
    }
}