michael@0: actual = '';
michael@0: expected = '10,';
michael@0: 
michael@0: function f(x) {
michael@0:   let (x = 10) {
michael@0:     for (var i = 0; i < 5; ++i) {
michael@0:       var g = function () {
michael@0: 	appendToActual(x);
michael@0:       };
michael@0:     }
michael@0:     g();
michael@0:   }
michael@0: }
michael@0: 
michael@0: f(1);
michael@0: 
michael@0: 
michael@0: assertEq(actual, expected)