diff --git a/spec/behavior/generated-parser-behavior.spec.js b/spec/behavior/generated-parser-behavior.spec.js
index abbc49c..dd524ad 100644
--- a/spec/behavior/generated-parser-behavior.spec.js
+++ b/spec/behavior/generated-parser-behavior.spec.js
@@ -436,112 +436,116 @@ describe("generated parser behavior", function() {
       });
 
       describe("label variables", function() {
-        it("can access label variables from preceding labeled elements in a sequence", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" b:"b" c:"c" &{ return a === "a" && b === "b" && c === "c"; }',
-                options
-              );
+        describe("in a containing sequence", function() {
+          it("can access variables defined by preceding labeled elements", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" b:"b" c:"c" &{ return a === "a" && b === "b" && c === "c"; }',
+                  options
+                );
 
-          expect(parser).toParse("abc");
+            expect(parser).toParse("abc");
+          });
         });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (group)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" &{ return a === "a"; })',
-                options
-              );
+        describe("in an outside sequence", function() {
+          it("can access variables defined by preceding labeled elements (group)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" &{ return a === "a"; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (optional)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" &{ return a === "a"; })?',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (optional)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" &{ return a === "a"; })?',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (zero or more)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" &{ return a === "a"; })*',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (zero or more)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" &{ return a === "a"; })*',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", [["b", undefined]]]);
-        });
+            expect(parser).toParse("ab", ["a", [["b", undefined]]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (one or more)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" &{ return a === "a"; })+',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (one or more)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" &{ return a === "a"; })+',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", [["b", undefined]]]);
-        });
+            expect(parser).toParse("ab", ["a", [["b", undefined]]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (text)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" $("b" &{ return a === "a"; })',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (text)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" $("b" &{ return a === "a"; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", "b"]);
-        });
+            expect(parser).toParse("ab", ["a", "b"]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (positive simple predicate)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" &("b" &{ return a === "a"; }) "b"',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (positive simple predicate)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" &("b" &{ return a === "a"; }) "b"',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", undefined, "b"]);
-        });
+            expect(parser).toParse("ab", ["a", undefined, "b"]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (negative simple predicate)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" !("b" &{ return a === "a"; }) "c"',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (negative simple predicate)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" !("b" &{ return a === "a"; }) "c"',
+                  options
+                );
 
-          expect(parser).toParse("ac", ["a", undefined, "c"]);
-        });
+            expect(parser).toParse("ac", ["a", undefined, "c"]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (label)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" b:("b" &{ return a === "a"; })',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (label)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" b:("b" &{ return a === "a"; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (sequence)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" ("c" &{ return a === "a"; }) "d")',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (sequence)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" ("c" &{ return a === "a"; }) "d")',
+                  options
+                );
 
-          expect(parser).toParse("abcd", ["a", ["b", ["c", undefined], "d"]]);
-        });
+            expect(parser).toParse("abcd", ["a", ["b", ["c", undefined], "d"]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (action)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" (b:("b" &{ return a === "a"; }) { return b; })',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (action)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" (b:("b" &{ return a === "a"; }) { return b; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (choice)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" / "c" &{ return a === "a"; } / "d")',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (choice)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" / "c" &{ return a === "a"; } / "d")',
+                  options
+                );
 
-          expect(parser).toParse("ac", ["a", ["c", undefined]]);
+            expect(parser).toParse("ac", ["a", ["c", undefined]]);
+          });
         });
       });
 
@@ -645,112 +649,116 @@ describe("generated parser behavior", function() {
       });
 
       describe("label variables", function() {
-        it("can access label variables from preceding labeled elements in a sequence", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" b:"b" c:"c" !{ return a !== "a" || b !== "b" || c !== "c"; }',
-                options
-              );
+        describe("in a containing sequence", function() {
+          it("can access variables defined by preceding labeled elements", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" b:"b" c:"c" !{ return a !== "a" || b !== "b" || c !== "c"; }',
+                  options
+                );
 
-          expect(parser).toParse("abc");
+            expect(parser).toParse("abc");
+          });
         });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (group)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" !{ return a !== "a"; })',
-                options
-              );
+        describe("in an outside sequence", function() {
+          it("can access variables defined by preceding labeled elements (group)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" !{ return a !== "a"; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (optional)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" !{ return a !== "a"; })?',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (optional)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" !{ return a !== "a"; })?',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (zero or more)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" !{ return a !== "a"; })*',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (zero or more)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" !{ return a !== "a"; })*',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", [["b", undefined]]]);
-        });
+            expect(parser).toParse("ab", ["a", [["b", undefined]]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (one or more)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" !{ return a !== "a"; })+',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (one or more)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" !{ return a !== "a"; })+',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", [["b", undefined]]]);
-        });
+            expect(parser).toParse("ab", ["a", [["b", undefined]]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (text)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" $("b" !{ return a !== "a"; })',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (text)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" $("b" !{ return a !== "a"; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", "b"]);
-        });
+            expect(parser).toParse("ab", ["a", "b"]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (positive simple predicate)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" &("b" !{ return a !== "a"; }) "b"',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (positive simple predicate)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" &("b" !{ return a !== "a"; }) "b"',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", undefined, "b"]);
-        });
+            expect(parser).toParse("ab", ["a", undefined, "b"]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (negative simple predicate)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" !("b" !{ return a !== "a"; }) "c"',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (negative simple predicate)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" !("b" !{ return a !== "a"; }) "c"',
+                  options
+                );
 
-          expect(parser).toParse("ac", ["a", undefined, "c"]);
-        });
+            expect(parser).toParse("ac", ["a", undefined, "c"]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (label)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" b:("b" !{ return a !== "a"; })',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (label)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" b:("b" !{ return a !== "a"; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (sequence)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" ("c" !{ return a !== "a"; }) "d")',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (sequence)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" ("c" !{ return a !== "a"; }) "d")',
+                  options
+                );
 
-          expect(parser).toParse("abcd", ["a", ["b", ["c", undefined], "d"]]);
-        });
+            expect(parser).toParse("abcd", ["a", ["b", ["c", undefined], "d"]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (action)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" (b:("b" !{ return a !== "a"; }) { return b; })',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (action)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" (b:("b" !{ return a !== "a"; }) { return b; })',
+                  options
+                );
 
-          expect(parser).toParse("ab", ["a", ["b", undefined]]);
-        });
+            expect(parser).toParse("ab", ["a", ["b", undefined]]);
+          });
 
-        it("can access label variables from preceding labeled elements in an outside sequence (choice)", function() {
-          var parser = PEG.buildParser(
-                'start = a:"a" ("b" / "c" !{ return a !== "a"; } / "d")',
-                options
-              );
+          it("can access variables defined by preceding labeled elements (choice)", function() {
+            var parser = PEG.buildParser(
+                  'start = a:"a" ("b" / "c" !{ return a !== "a"; } / "d")',
+                  options
+                );
 
-          expect(parser).toParse("ac", ["a", ["c", undefined]]);
+            expect(parser).toParse("ac", ["a", ["c", undefined]]);
+          });
         });
       });
 
@@ -1044,118 +1052,122 @@ describe("generated parser behavior", function() {
         });
 
         describe("label variables", function() {
-          it("can access label variables from a labeled expression", function() {
-            var parser = PEG.buildParser('start = a:"a" { return a; }', options);
+          describe("in the expression", function() {
+            it("can access label variables defined by a labeled expression", function() {
+              var parser = PEG.buildParser('start = a:"a" { return a; }', options);
 
-            expect(parser).toParse("a", "a");
-          });
+              expect(parser).toParse("a", "a");
+            });
 
-          it("can access label variables from a sequence with labeled elements", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" b:"b" c:"c" { return [a, b, c]; }',
-                  options
-                );
+            it("can access label variables defined by labeled sequence elements", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" b:"b" c:"c" { return [a, b, c]; }',
+                    options
+                  );
 
-            expect(parser).toParse("abc", ["a", "b", "c"]);
+              expect(parser).toParse("abc", ["a", "b", "c"]);
+            });
           });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (group)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" ("b" { return a; })',
-                  options
-                );
+          describe("in an outside sequence", function() {
+            it("can access variables defined by preceding labeled elements (group)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" ("b" { return a; })',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", "a"]);
-          });
+              expect(parser).toParse("ab", ["a", "a"]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (optional)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" ("b" { return a; })?',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (optional)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" ("b" { return a; })?',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", "a"]);
-          });
+              expect(parser).toParse("ab", ["a", "a"]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (zero or more)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" ("b" { return a; })*',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (zero or more)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" ("b" { return a; })*',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", ["a"]]);
-          });
+              expect(parser).toParse("ab", ["a", ["a"]]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (one or more)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" ("b" { return a; })+',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (one or more)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" ("b" { return a; })+',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", ["a"]]);
-          });
+              expect(parser).toParse("ab", ["a", ["a"]]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (text)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" $("b" { return a; })',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (text)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" $("b" { return a; })',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", "b"]);
-          });
+              expect(parser).toParse("ab", ["a", "b"]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (positive simple predicate)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" &("b" { return a; }) "b"',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (positive simple predicate)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" &("b" { return a; }) "b"',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", undefined, "b"]);
-          });
+              expect(parser).toParse("ab", ["a", undefined, "b"]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (negative simple predicate)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" !("b" { return a; }) "c"',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (negative simple predicate)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" !("b" { return a; }) "c"',
+                    options
+                  );
 
-            expect(parser).toParse("ac", ["a", undefined, "c"]);
-          });
+              expect(parser).toParse("ac", ["a", undefined, "c"]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (label)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" b:("b" { return a; })',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (label)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" b:("b" { return a; })',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", "a"]);
-          });
+              expect(parser).toParse("ab", ["a", "a"]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (sequence)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" ("b" ("c" { return a; }) "d")',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (sequence)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" ("b" ("c" { return a; }) "d")',
+                    options
+                  );
 
-            expect(parser).toParse("abcd", ["a", ["b", "a", "d"]]);
-          });
+              expect(parser).toParse("abcd", ["a", ["b", "a", "d"]]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (action)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" (b:("b" { return a; }) { return b; })',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (action)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" (b:("b" { return a; }) { return b; })',
+                    options
+                  );
 
-            expect(parser).toParse("ab", ["a", "a"]);
-          });
+              expect(parser).toParse("ab", ["a", "a"]);
+            });
 
-          it("can access label variables from preceding labeled elements in an outside sequence (choice)", function() {
-            var parser = PEG.buildParser(
-                  'start = a:"a" ("b" / "c" { return a; } / "d")',
-                  options
-                );
+            it("can access variables defined by preceding labeled elements (choice)", function() {
+              var parser = PEG.buildParser(
+                    'start = a:"a" ("b" / "c" { return a; } / "d")',
+                    options
+                  );
 
-            expect(parser).toParse("ac", ["a", "a"]);
+              expect(parser).toParse("ac", ["a", "a"]);
+            });
           });
         });