diff --git a/assemble.rkt b/assemble.rkt
index 7009864..67bc917 100644
--- a/assemble.rkt
+++ b/assemble.rkt
@@ -319,7 +319,7 @@ EOF
       (let*: ([test : PrimitiveTest (TestAndBranchStatement-op stmt)])
              (cond
                [(eq? test 'false?)
-                (format "if (! ~a) { ~a }"
+                (format "if (~a === false) { ~a }"
                         (assemble-reg (make-Reg (TestAndBranchStatement-register stmt)))
                         (assemble-jump (make-Label (TestAndBranchStatement-label stmt))))]
                [(eq? test 'one?)
diff --git a/kernel-primitives.rkt b/kernel-primitives.rkt
index b9604a5..c30cef0 100644
--- a/kernel-primitives.rkt
+++ b/kernel-primitives.rkt
@@ -12,7 +12,7 @@
 
 
 ;; The following are primitives that the compiler knows about:
-(define-type KernelPrimitiveName (U) #;(U '+
+(define-type KernelPrimitiveName (U '+
                                     '-
                                     '*
                                     '/
diff --git a/runtime.js b/runtime.js
index e159416..0e9fda4 100644
--- a/runtime.js
+++ b/runtime.js
@@ -34,7 +34,8 @@
 
 
     var isPair = function(x) { return (typeof(x) == 'object' && 
-				       x.length === 2) };
+				       x.length === 2 &&
+				       x.type !== 'vector') };
     var isList = function(x) {
 	while (x !== NULL) {
 	    if (typeof(x) == 'object' && x.length === 2) {
@@ -47,7 +48,7 @@
     };
 
     var isVector = function(x) { return (typeof(x) == 'object' && 
-					 x.length !== undefined) };
+					 x.type === 'vector') };
 
     var Machine = function() {
 	this.callsBeforeTrampoline = 100;
@@ -739,6 +740,7 @@
 	for (i = 0; i < MACHINE.argcount; i++) {
 	    result.push(MACHINE.env[MACHINE.env.length-1-i]);
 	}
+	result.type = 'vector';
 	return result;
     };
     Primitives['vector'].arity = new ArityAtLeast(0);
@@ -769,6 +771,7 @@
 	    result.push(firstArg[0]);
 	    firstArg = firstArg[1];
 	}
+	result.type='vector';
 	return result;
     };
     Primitives['list->vector'].arity = 1;
@@ -835,6 +838,7 @@
 	for(var i = 0; i < length; i++) {
 	    arr[i] = value;
 	}
+	arr.type='vector';
 	return arr;
     };
     Primitives['make-vector'].arity = [1, [2, NULL]];
@@ -969,6 +973,28 @@
     Primitives['member'].displayName = 'member';
 
 
+
+    Primitives['reverse'] = function(MACHINE) {
+	var rev = NULL;
+	var lst = MACHINE.env[MACHINE.env.length-1];
+	while(lst !== NULL) {
+	    testArgument(MACHINE,
+			 'pair', isPair, lst, 0, 'reverse');
+	    rev = [lst[0], rev];
+	    lst = lst[1];
+	}
+	return rev;
+    };
+    Primitives['reverse'].arity = 1;
+    Primitives['reverse'].displayName = 'reverse';
+
+
+
+
+
+
+
+
     // recomputeGas: state number -> number
     var recomputeMaxNumBouncesBeforeYield = function(MACHINE, observedDelay) {
 	// We'd like to see a delay of DESIRED_DELAY_BETWEEN_BOUNCES so
@@ -987,22 +1013,6 @@
 
 
 
-    Primitives['reverse'] = function(MACHINE) {
-	var rev = NULL;
-	var lst = MACHINE.env[MACHINE.env.length-1];
-	while(lst !== NULL) {
-	    testArgument(MACHINE,
-			 'pair', isPair, lst, 0, 'reverse');
-	    rev = [lst[0], rev];
-	    lst = lst[1];
-	}
-	return rev;
-    };
-    Primitives['reverse'].arity = 1;
-    Primitives['reverse'].displayName = 'reverse';
-
-
-
 
     var trampoline = function(MACHINE, initialJump) {
 	var thunk = initialJump;
diff --git a/test-browser-evaluate.rkt b/test-browser-evaluate.rkt
index f6e9ef1..1b3c6c6 100644
--- a/test-browser-evaluate.rkt
+++ b/test-browser-evaluate.rkt
@@ -144,6 +144,11 @@ EOF
 (test '(displayln (add1 1))
       "2\n")
 
+
+(test '(displayln (if 0 1 2))
+      "1\n")
+
+
 (test/exn '(displayln (add1 "0"))
           "Error: add1: expected number as argument 1 but received 0")
 
@@ -459,6 +464,16 @@ EOF
 			  '(1 2 (3))))
       "true\n")
 
+
+(test '(displayln (equal? (list 1 2 (vector 3))
+			  (list 1 2 (vector 3))))
+      "true\n")
+
+
+(test '(displayln (equal? (list 1 2 (vector 4))
+			  (list 1 2 (vector 3))))
+      "false\n")
+
       
 
 
diff --git a/tests/earley/earley.sch b/tests/earley/earley.sch
index 56f7f6c..b27dd88 100644
--- a/tests/earley/earley.sch
+++ b/tests/earley/earley.sch
@@ -820,8 +820,6 @@
 			     (lambda (l) 
 			       (map (lambda (x) (list x x)) l)))))
          (let ((x (p (vector->list (make-vector k 'a))))) 
-	   ;(displayln x)
-	   ;(displayln (parse->trees x 's '0 k)) ;; dyoo : temporary
 	   (display (length (parse->trees x 's '0 k))) 
 	   (newline)))))
    (test '12))