diff --git a/triple/node/node.go b/triple/node/node.go
index dc68f32f..e96a7338 100644
--- a/triple/node/node.go
+++ b/triple/node/node.go
@@ -36,8 +36,11 @@ func (t *Type) String() string {
 // Covariant checks for given two types A and B, A covariant B if B _is a_ A.
 // In other word, A _covariant_ B if B is a prefix of A.
 func (t *Type) Covariant(ot *Type) bool {
-	// TODO: is /ab covariant of /a ?
-	return strings.HasPrefix(t.String(), ot.String())
+	if !strings.HasPrefix(t.String(), ot.String()) {
+		return false
+	}
+	// /type/foo is covarian of /type, but /typefoo is not covatiant of /type.
+	return len(t.String()) == len(ot.String()) || t.String()[len(ot.String())] == '/'
 }
 
 // ID represents a node ID.
diff --git a/triple/node/node_test.go b/triple/node/node_test.go
index 347db100..37246476 100644
--- a/triple/node/node_test.go
+++ b/triple/node/node_test.go
@@ -65,12 +65,19 @@ func TestNewTypeString(t *testing.T) {
 	if err != nil {
 		t.Errorf("node.NewType(\"/some/type/a\") should never fail with error %v", err)
 	}
+	tAB, err := NewType("/some/type/ab")
+	if err != nil {
+		t.Errorf("node.NewType(\"/some/type/ab\") should never fail with error %v", err)
+	}
 	if tA.Covariant(tB) {
 		t.Errorf("node.Covariant: %q should not be market as covariant of %q", tA, tB)
 	}
 	if !tB.Covariant(tA) {
 		t.Errorf("node.Covariant: %q should not be market as covariant of %q", tB, tA)
 	}
+	if tAB.Covariant(tB) {
+		t.Errorf("node.Covariant: %q should not be market as covariant of %q", tAB, tB)
+	}
 }
 
 func TestNewNodeFromString(t *testing.T) {
diff --git a/triple/predicate/predicate.go b/triple/predicate/predicate.go
index 22fc389d..8f44c9fa 100644
--- a/triple/predicate/predicate.go
+++ b/triple/predicate/predicate.go
@@ -18,6 +18,7 @@ package predicate
 import (
 	"encoding/base64"
 	"fmt"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -80,7 +81,11 @@ func Parse(s string) (*Predicate, error) {
 	if idx < 0 {
 		return nil, fmt.Errorf("predicate.Parse could not find anchor definition in %s", raw)
 	}
-	id, ta := raw[1:idx], raw[idx+3:len(raw)-1]
+	id, ta := raw[0:idx+1], raw[idx+3:len(raw)-1]
+	id, err := strconv.Unquote(id)
+	if err != nil {
+		return nil, fmt.Errorf("predicate.Parse can't unquote id in %s: %v", raw, err)
+	}
 	// TODO: if id has \" inside, it should be unquoted.
 	if ta == "" {
 		return &Predicate{
diff --git a/triple/predicate/predicate_test.go b/triple/predicate/predicate_test.go
index 920b650a..72539205 100644
--- a/triple/predicate/predicate_test.go
+++ b/triple/predicate/predicate_test.go
@@ -106,7 +106,7 @@ func TestParse(t *testing.T) {
 	pretty := fmt.Sprintf("\"bar\"@[%s]", date)
 	got, err := Parse(pretty)
 	if err != nil {
-		t.Errorf("predicate.Parse could not create a predicate for %s with error %v", pretty, err)
+		t.Fatalf("predicate.Parse could not create a predicate for %s with error %v", pretty, err)
 	}
 	if got.Type() != Temporal {
 		t.Errorf("predicate.Parse should have returned a temporal predicate, instead returned %s", got)
@@ -121,9 +121,29 @@ func TestParse(t *testing.T) {
 
 	imm, err := Parse("\"foo\"@[]")
 	if err != nil {
-		t.Errorf("predicate.Parse failed to immutable predicate \"foo\"@[] with error %v", err)
+		t.Errorf("predicate.Parse failed to parse immutable predicate \"foo\"@[] with error %v", err)
 	}
 	if imm.Type() != Immutable || imm.ID() != "foo" {
-		t.Errorf("predicate.Parse failed to immutable predicate \"foo\"@[]; got %v instead", imm)
+		t.Errorf("predicate.Parse failed to parse immutable predicate \"foo\"@[]; got %v instead", imm)
+	}
+}
+
+func TestQuotedID(t *testing.T) {
+	const id = "ba\"r"
+	const pretty = "\"ba\\\"r\"@[]"
+	immut, err := NewImmutable(id)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, want := immut.String(), pretty; got != want {
+		t.Fatalf("predicate.String() = %v; want %v", got, want)
+	}
+
+	immut, err = Parse(pretty)
+	if err != nil {
+		t.Fatalf("predicate.Parse failed to parse immutable predicate \"foo\"@[] with error %v", err)
+	}
+	if immut.Type() != Immutable || immut.ID() != id {
+		t.Errorf("predicate.Parse failed to parse immutable predicate %v; got %v instead", pretty, immut)
 	}
 }