diff --git a/x/logic/predicate/address_test.go b/x/logic/predicate/address_test.go
new file mode 100644
index 00000000..d6b7d866
--- /dev/null
+++ b/x/logic/predicate/address_test.go
@@ -0,0 +1,103 @@
+package predicate
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/cosmos/cosmos-sdk/store"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/ichiban/prolog/engine"
+	"github.com/okp4/okp4d/x/logic/testutil"
+	"github.com/okp4/okp4d/x/logic/types"
+	. "github.com/smartystreets/goconvey/convey"
+	"github.com/tendermint/tendermint/libs/log"
+	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
+	tmdb "github.com/tendermint/tm-db"
+)
+
+func TestBech32(t *testing.T) {
+	Convey("Given a test cases", t, func() {
+		cases := []struct {
+			program     string
+			query       string
+			wantResult  []types.TermResults
+			wantError   error
+			wantSuccess bool
+		}{
+			{
+				query: `bech32_address(Hrp, Address, 'okp415wn30a9z4uc692s0kkx5fp5d4qfr3ac7sj9dqn').`,
+				wantResult: []types.TermResults{{
+					"Hrp":     "okp4",
+					"Address": "[163,167,23,244,162,175,49,162,170,15,181,141,68,134,141,168,18,56,247,30]",
+				}},
+				wantSuccess: true,
+			},
+			{
+				query: `bech32_address('okp4', Address, 'okp415wn30a9z4uc692s0kkx5fp5d4qfr3ac7sj9dqn').`,
+				wantResult: []types.TermResults{{
+					"Address": "[163,167,23,244,162,175,49,162,170,15,181,141,68,134,141,168,18,56,247,30]",
+				}},
+				wantSuccess: true,
+			},
+			{
+				query:       `bech32_address('okp5', Address, 'okp415wn30a9z4uc692s0kkx5fp5d4qfr3ac7sj9dqn').`,
+				wantSuccess: false,
+			},
+		}
+		for nc, tc := range cases {
+			Convey(fmt.Sprintf("Given the query #%d: %s", nc, tc.query), func() {
+				Convey("and a context", func() {
+					db := tmdb.NewMemDB()
+					stateStore := store.NewCommitMultiStore(db)
+					ctx := sdk.NewContext(stateStore, tmproto.Header{}, false, log.NewNopLogger())
+
+					Convey("and a vm", func() {
+						interpreter := testutil.NewInterpreterMust(ctx)
+						interpreter.Register3(engine.NewAtom("bech32_address"), Bech32Address)
+
+						err := interpreter.Compile(ctx, tc.program)
+						So(err, ShouldBeNil)
+
+						Convey("When the predicate is called", func() {
+							sols, err := interpreter.QueryContext(ctx, tc.query)
+
+							Convey("Then the error should be nil", func() {
+								So(err, ShouldBeNil)
+								So(sols, ShouldNotBeNil)
+
+								Convey("and the bindings should be as expected", func() {
+									var got []types.TermResults
+									for sols.Next() {
+										m := types.TermResults{}
+										err := sols.Scan(m)
+										So(err, ShouldBeNil)
+
+										got = append(got, m)
+									}
+									if tc.wantError != nil {
+										So(sols.Err(), ShouldNotBeNil)
+										So(sols.Err().Error(), ShouldEqual, tc.wantError.Error())
+									} else {
+										So(sols.Err(), ShouldBeNil)
+
+										if tc.wantSuccess {
+											So(len(got), ShouldBeGreaterThan, 0)
+											So(len(got), ShouldEqual, len(tc.wantResult))
+											for iGot, resultGot := range got {
+												for varGot, termGot := range resultGot {
+													So(testutil.ReindexUnknownVariables(termGot), ShouldEqual, tc.wantResult[iGot][varGot])
+												}
+											}
+										} else {
+											So(len(got), ShouldEqual, 0)
+										}
+									}
+								})
+							})
+						})
+					})
+				})
+			})
+		}
+	})
+}