diff --git a/clox/clox b/clox/clox
index 109e9f2..72d7760 100755
Binary files a/clox/clox and b/clox/clox differ
diff --git a/clox/compiler.c b/clox/compiler.c
index aafb558..67e1ab2 100644
--- a/clox/compiler.c
+++ b/clox/compiler.c
@@ -135,10 +135,17 @@ static void binary() {
   parsePrecedence((Precedence)(rule->precedence + 1));
 
   switch (operatorType) {
+    case TOKEN_BANG_EQUAL:    emitBytes(OP_EQUAL, OP_NOT); break;
+    case TOKEN_EQUAL_EQUAL:   emitByte(OP_EQUAL); break;
+    case TOKEN_GREATER:       emitByte(OP_GREATER); break;
+    case TOKEN_GREATER_EQUAL: emitBytes(OP_LESS, OP_NOT); break;
+    case TOKEN_LESS:          emitByte(OP_LESS); break;
+    case TOKEN_LESS_EQUAL:    emitBytes(OP_GREATER, OP_NOT); break;
     case TOKEN_PLUS:          emitByte(OP_ADD); break;
     case TOKEN_MINUS:         emitByte(OP_SUBTRACT); break;
     case TOKEN_STAR:          emitByte(OP_MULTIPLY); break;
     case TOKEN_SLASH:         emitByte(OP_DIVIDE); break;
+
     default: return; // Unreachable.
   }
 }
@@ -211,13 +218,13 @@ ParseRule rules[] = {
   [TOKEN_SLASH]         = {NULL,     binary, PREC_FACTOR},
   [TOKEN_STAR]          = {NULL,     binary, PREC_FACTOR},
   [TOKEN_BANG]          = {unary,    NULL,   PREC_NONE},
-  [TOKEN_BANG_EQUAL]    = {NULL,     NULL,   PREC_NONE},
+  [TOKEN_BANG_EQUAL]    = {NULL,     binary,   PREC_EQUALITY},
   [TOKEN_EQUAL]         = {NULL,     NULL,   PREC_NONE},
-  [TOKEN_EQUAL_EQUAL]   = {NULL,     NULL,   PREC_NONE},
-  [TOKEN_GREATER]       = {NULL,     NULL,   PREC_NONE},
-  [TOKEN_GREATER_EQUAL] = {NULL,     NULL,   PREC_NONE},
-  [TOKEN_LESS]          = {NULL,     NULL,   PREC_NONE},
-  [TOKEN_LESS_EQUAL]    = {NULL,     NULL,   PREC_NONE},
+  [TOKEN_EQUAL_EQUAL]   = {NULL,     binary, PREC_EQUALITY},
+  [TOKEN_GREATER]       = {NULL,     binary, PREC_COMPARISON},
+  [TOKEN_GREATER_EQUAL] = {NULL,     binary, PREC_COMPARISON},
+  [TOKEN_LESS]          = {NULL,     binary, PREC_COMPARISON},
+  [TOKEN_LESS_EQUAL]    = {NULL,     binary, PREC_COMPARISON},
   [TOKEN_IDENTIFIER]    = {NULL,     NULL,   PREC_NONE},
   [TOKEN_STRING]        = {NULL,     NULL,   PREC_NONE},
   [TOKEN_NUMBER]        = {number,   NULL,   PREC_NONE},
diff --git a/clox/compiler.o b/clox/compiler.o
index 7f30988..541d9fb 100644
Binary files a/clox/compiler.o and b/clox/compiler.o differ
diff --git a/clox/debug.o b/clox/debug.o
index 1431a55..e37916e 100644
Binary files a/clox/debug.o and b/clox/debug.o differ
diff --git a/clox/tests/chapter18_expr_tests.lox b/clox/tests/chapter18_expr_tests.lox
new file mode 100644
index 0000000..bbc9553
--- /dev/null
+++ b/clox/tests/chapter18_expr_tests.lox
@@ -0,0 +1 @@
+!(5 - 4 > 3 * 2 == !nil)
diff --git a/clox/value.c b/clox/value.c
index 19b7c0b..f1f3727 100644
--- a/clox/value.c
+++ b/clox/value.c
@@ -42,4 +42,3 @@ bool valuesEqual(Value a, Value b) {
     default:         return false; // Unreachable.
   }
 }
-
diff --git a/clox/value.h b/clox/value.h
index ee41d23..c8af524 100644
--- a/clox/value.h
+++ b/clox/value.h
@@ -37,6 +37,7 @@ typedef struct {
   Value* values;
 } ValueArray;
 
+bool valuesEqual(Value a, Value b);
 void initValueArray(ValueArray* array);
 void writeValueArray(ValueArray* array, Value value);
 void freeValueArray(ValueArray* array);
diff --git a/clox/value.o b/clox/value.o
index 2a9e016..1d7ac1d 100644
Binary files a/clox/value.o and b/clox/value.o differ
diff --git a/clox/vm.c b/clox/vm.c
index 4d4d599..8e70669 100644
--- a/clox/vm.c
+++ b/clox/vm.c
@@ -83,6 +83,12 @@ static InterpretResult run() {
       case OP_NIL: push(NIL_VAL); break;
       case OP_TRUE: push(BOOL_VAL(true)); break;
       case OP_FALSE: push(BOOL_VAL(false)); break;
+      case OP_EQUAL: {
+        Value b = pop();
+        Value a = pop();
+        push(BOOL_VAL(valuesEqual(a, b)));
+        break;
+      }
       case OP_GREATER:  BINARY_OP(BOOL_VAL, >); break;
       case OP_LESS:     BINARY_OP(BOOL_VAL, <); break;
       case OP_ADD:      BINARY_OP(NUMBER_VAL, +); break;
diff --git a/clox/vm.o b/clox/vm.o
index 287fae9..0873f42 100644
Binary files a/clox/vm.o and b/clox/vm.o differ