diff --git a/ucl/builtins.go b/ucl/builtins.go
index e984786..4841a3a 100644
--- a/ucl/builtins.go
+++ b/ucl/builtins.go
@@ -88,17 +88,85 @@ func eqBuiltin(ctx context.Context, args invocationArgs) (object, error) {
 	l := args.args[0]
 	r := args.args[1]
 
+	return boolObject(objectsEqual(l, r)), nil
+}
+
+func neBuiltin(ctx context.Context, args invocationArgs) (object, error) {
+	if err := args.expectArgn(2); err != nil {
+		return nil, err
+	}
+
+	l := args.args[0]
+	r := args.args[1]
+
+	return boolObject(!objectsEqual(l, r)), nil
+}
+
+var errObjectsNotEqual = errors.New("objects not equal")
+
+func objectsEqual(l, r object) bool {
+	if l == nil || r == nil {
+		return l == nil && r == nil
+	}
+
 	switch lv := l.(type) {
 	case strObject:
 		if rv, ok := r.(strObject); ok {
-			return boolObject(lv == rv), nil
+			return lv == rv
 		}
 	case intObject:
 		if rv, ok := r.(intObject); ok {
-			return boolObject(lv == rv), nil
+			return lv == rv
 		}
+	case boolObject:
+		if rv, ok := r.(boolObject); ok {
+			return lv == rv
+		}
+	case listable:
+		rv, ok := r.(listable)
+		if !ok {
+			return false
+		}
+
+		if lv.Len() != rv.Len() {
+			return false
+		}
+		for i := 0; i < lv.Len(); i++ {
+			if !objectsEqual(lv.Index(i), rv.Index(i)) {
+				return false
+			}
+		}
+		return true
+	case hashable:
+		rv, ok := r.(hashable)
+		if !ok {
+			return false
+		}
+
+		if lv.Len() != rv.Len() {
+			return false
+		}
+		if err := lv.Each(func(k string, lkv object) error {
+			rkv := rv.Value(k)
+			if rkv == nil {
+				return errObjectsNotEqual
+			} else if !objectsEqual(lkv, rkv) {
+				return errObjectsNotEqual
+			}
+			return nil
+		}); err != nil {
+			return false
+		}
+		return true
+	case OpaqueObject:
+		rv, ok := r.(OpaqueObject)
+		if !ok {
+			return false
+		}
+
+		return lv.v == rv.v
 	}
-	return boolObject(false), nil
+	return false
 }
 
 func concatBuiltin(ctx context.Context, args invocationArgs) (object, error) {
diff --git a/ucl/inst.go b/ucl/inst.go
index a4d1128..66c323b 100644
--- a/ucl/inst.go
+++ b/ucl/inst.go
@@ -61,6 +61,8 @@ func New(opts ...InstOption) *Inst {
 	rootEC.addCmd("reduce", invokableFunc(reduceBuiltin))
 
 	rootEC.addCmd("eq", invokableFunc(eqBuiltin))
+	rootEC.addCmd("ne", invokableFunc(neBuiltin))
+
 	rootEC.addCmd("add", invokableFunc(addBuiltin))
 
 	rootEC.addCmd("cat", invokableFunc(concatBuiltin))
@@ -88,6 +90,14 @@ func New(opts ...InstOption) *Inst {
 	return inst
 }
 
+func (inst *Inst) SetVar(name string, value any) {
+	obj, err := fromGoValue(value)
+	if err != nil {
+		return
+	}
+	inst.rootEC.setOrDefineVar(name, obj)
+}
+
 func (inst *Inst) Out() io.Writer {
 	if inst.out == nil {
 		return os.Stdout
diff --git a/ucl/objs.go b/ucl/objs.go
index 5527c85..6580c9c 100644
--- a/ucl/objs.go
+++ b/ucl/objs.go
@@ -118,6 +118,8 @@ func toGoValue(obj object) (interface{}, bool) {
 		return string(v), true
 	case intObject:
 		return int(v), true
+	case boolObject:
+		return bool(v), true
 	case listObject:
 		xs := make([]interface{}, 0, len(v))
 		for _, va := range v {
@@ -159,6 +161,8 @@ func fromGoValue(v any) (object, error) {
 		return strObject(t), nil
 	case int:
 		return intObject(t), nil
+	case bool:
+		return boolObject(t), nil
 	}
 
 	return fromGoReflectValue(reflect.ValueOf(v))
diff --git a/ucl/testbuiltins_test.go b/ucl/testbuiltins_test.go
index 34e0220..d9133d6 100644
--- a/ucl/testbuiltins_test.go
+++ b/ucl/testbuiltins_test.go
@@ -229,16 +229,16 @@ func TestBuiltins_Break(t *testing.T) {
 		expr string
 		want string
 	}{
-		//{desc: "break unconditionally returning nothing", expr: `
-		//	foreach ["1" "2" "3"] { |v|
-		//		break
-		//		echo $v
-		//	}`, want: "(nil)\n"},
-		//{desc: "break conditionally returning nothing", expr: `
-		//	foreach ["1" "2" "3"] { |v|
-		//		echo $v
-		//		if (eq $v "2") { break }
-		//	}`, want: "1\n2\n(nil)\n"},
+		{desc: "break unconditionally returning nothing", expr: `
+			foreach ["1" "2" "3"] { |v|
+				break
+				echo $v
+			}`, want: "(nil)\n"},
+		{desc: "break conditionally returning nothing", expr: `
+			foreach ["1" "2" "3"] { |v|
+				echo $v
+				if (eq $v "2") { break }
+			}`, want: "1\n2\n(nil)\n"},
 		{desc: "break inner loop only returning nothing", expr: `
 			foreach ["a" "b"] { |u|
 				foreach ["1" "2" "3"] { |v|
@@ -246,11 +246,11 @@ func TestBuiltins_Break(t *testing.T) {
 					if (eq $v "2") { break }
 				}
 			}`, want: "a1\na2\nb1\nb2\n(nil)\n"},
-		//{desc: "break returning value", expr: `
-		//	echo (foreach ["1" "2" "3"] { |v|
-		//		echo $v
-		//		if (eq $v "2") { break "hello" }
-		//	})`, want: "1\n2\nhello\n(nil)\n"},
+		{desc: "break returning value", expr: `
+			echo (foreach ["1" "2" "3"] { |v|
+				echo $v
+				if (eq $v "2") { break "hello" }
+			})`, want: "1\n2\nhello\n(nil)\n"},
 	}
 
 	for _, tt := range tests {
@@ -891,3 +891,72 @@ func TestBuiltins_Reduce(t *testing.T) {
 		})
 	}
 }
+
+func TestBuiltins_EqNe(t *testing.T) {
+	tests := []struct {
+		desc string
+		expr string
+		want bool
+	}{
+		{desc: "equal strs 1", expr: `eq "hello" "hello"`, want: true},
+		{desc: "equal strs 2", expr: `eq "bla" "bla"`, want: true},
+		{desc: "equal strs 3", expr: `eq "" ""`, want: true},
+		{desc: "equal ints 1", expr: `eq 123 123`, want: true},
+		{desc: "equal ints 2", expr: `eq -21 -21`, want: true},
+		{desc: "equal ints 3", expr: `eq 0 0`, want: true},
+		{desc: "equal lists 1", expr: `eq [1 2 3] [1 2 3]`, want: true},
+		{desc: "equal lists 2", expr: `eq ["foo" "bar"] ["foo" "bar"]`, want: true},
+		{desc: "equal lists 3", expr: `eq [] []`, want: true},
+		{desc: "equal hashes 1", expr: `eq ["this":1 "that":"thing"] ["that":"thing" "this":1]`, want: true},
+		{desc: "equal hashes 2", expr: `eq ["foo":"bar"] ["foo":"bar"]`, want: true},
+		{desc: "equal bools 1", expr: `eq true true`, want: true},
+		{desc: "equal bools 2", expr: `eq false false`, want: true},
+		{desc: "equal nil 1", expr: `eq () ()`, want: true},
+		{desc: "equal opaque 1", expr: `eq $hello $hello`, want: true},
+		{desc: "equal opaque 2", expr: `eq $world $world`, want: true},
+
+		{desc: "not equal strs 1", expr: `eq "hello" "world"`, want: false},
+		{desc: "not equal strs 2", expr: `eq "bla" "BLA"`, want: false},
+		{desc: "not equal int 1", expr: `eq 131 313`, want: false},
+		{desc: "not equal int 2", expr: `eq -2 2`, want: false},
+		{desc: "not equal lists 1", expr: `eq [1 2 3] [1 2]`, want: false},
+		{desc: "not equal lists 2", expr: `eq ["123" "234"] [123 234]`, want: false},
+		{desc: "not equal hashes 1", expr: `eq ["this":1 "that":"thing"] ["that":"thing"]`, want: false},
+		{desc: "not equal hashes 2", expr: `eq ["this":1 "that":"thing"] ["this":1 "that":"thing" "other":"thing"]`, want: false},
+		{desc: "not equal hashes 3", expr: `eq ["this":1 "that":"thing"] ["this":"1" "that":"other"]`, want: false},
+		{desc: "not equal opaque 1", expr: `eq $hello $world`, want: false},
+		{desc: "not equal opaque 2", expr: `eq $hello "hello"`, want: false},
+
+		{desc: "not equal types 1", expr: `eq "123" 123`, want: false},
+		{desc: "not equal types 2", expr: `eq 0 ""`, want: false},
+		{desc: "not equal types 3", expr: `eq [] [:]`, want: false},
+		{desc: "not equal types 4", expr: `eq ["23"] "23"`, want: false},
+		{desc: "not equal types 5", expr: `eq true ()`, want: false},
+		{desc: "not equal types 6", expr: `eq () false`, want: false},
+		{desc: "not equal types 7", expr: `eq () "yes"`, want: false},
+		{desc: "not equal types 8", expr: `eq () $world`, want: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			type testProxyObject struct {
+				v string
+			}
+
+			ctx := context.Background()
+			outW := bytes.NewBuffer(nil)
+
+			inst := New(WithOut(outW), WithTestBuiltin())
+			inst.SetVar("hello", Opaque(testProxyObject{v: "hello"}))
+			inst.SetVar("world", Opaque(testProxyObject{v: "world"}))
+
+			eqRes, err := inst.Eval(ctx, tt.expr)
+			assert.NoError(t, err)
+			assert.Equal(t, tt.want, eqRes)
+
+			neRes, err := inst.Eval(ctx, strings.ReplaceAll(tt.expr, "eq", "ne"))
+			assert.NoError(t, err)
+			assert.Equal(t, !tt.want, neRes)
+		})
+	}
+}