diff --git a/include/mcl/bn.hpp b/include/mcl/bn.hpp
index cc99de6..f81e6ea 100644
--- a/include/mcl/bn.hpp
+++ b/include/mcl/bn.hpp
@@ -324,7 +324,7 @@ struct BNT {
 		R.y = theta * (t2 + t1 - t3 - t4) - Y1 * t3;
 		R.z = Z1 * t3;
 		l.a = theta * X2 - lambda * Y2;
-		Fp2::mulXi(l.a, l.a);
+		Fp2::mul_xi(l.a, l.a);
 		l.b = lambda;
 		l.c = -theta;
 #else
@@ -351,7 +351,7 @@ struct BNT {
 		mulOpt1(T1, t2, Q.x);
 		mulOpt1(T2, t1, Q.y);
 		Fp2::sub(t2, T1, T2);
-		Fp2::mulXi(l.a, t2);
+		Fp2::mul_xi(l.a, t2);
 		l.b = t1;
 #endif
 	}
diff --git a/include/mcl/fp_tower.hpp b/include/mcl/fp_tower.hpp
index b544b6d..166194a 100644
--- a/include/mcl/fp_tower.hpp
+++ b/include/mcl/fp_tower.hpp
@@ -82,7 +82,7 @@ public:
 	static inline void inv(Fp2T& y, const Fp2T& x) { Fp::op_.fp2_inv(y.a.v_, x.a.v_); }
 	static inline void neg(Fp2T& y, const Fp2T& x) { Fp::op_.fp2_neg(y.a.v_, x.a.v_); }
 	static inline void sqr(Fp2T& y, const Fp2T& x) { Fp::op_.fp2_sqr(y.a.v_, x.a.v_); }
-	static inline void mulXi(Fp2T& y, const Fp2T& x) { Fp::op_.fp2_mulXi(y.a.v_, x.a.v_); }
+	static inline void mul_xi(Fp2T& y, const Fp2T& x) { Fp::op_.fp2_mul_xi(y.a.v_, x.a.v_); }
 	static inline void divBy2(Fp2T& y, const Fp2T& x)
 	{
 		Fp::divBy2(y.a, x.a);
@@ -125,7 +125,7 @@ public:
 		op.fp2_neg = fp2_negW;
 		op.fp2_inv = fp2_invW;
 		op.fp2_sqr = fp2_sqrW;
-		op.fp2_mulXi = fp2_mulXiW;
+		op.fp2_mul_xi = fp2_mul_xiW;
 	}
 private:
 	/*
@@ -242,7 +242,7 @@ private:
 		y = (a + bi)xi = (a + bi)(xi_a + i)
 		=(a * x_ic - b) + (a + b xi_a)i
 	*/
-	static inline void fp2_mulXiW(Unit *y, const Unit *x)
+	static inline void fp2_mul_xiW(Unit *y, const Unit *x)
 	{
 		const Fp *px = reinterpret_cast<const Fp*>(x);
 		Fp *py = reinterpret_cast<Fp*>(y);
@@ -399,12 +399,12 @@ struct Fp6T : public fp::Operator<Fp6T<Fp> > {
 		y.c += x.b; // a + b + c
 		Fp2::sqr(y.b, y.c); // (a + b + c)^2, destroy y.b
 		y.b -= t2; // (a + b + c)^2 - 2bc
-		Fp2::mulXi(t2, t2); // 2bc xi
+		Fp2::mul_xi(t2, t2); // 2bc xi
 		Fp2::sqr(y.a, x.a); // a^2, destroy y.a
 		y.b -= y.a; // (a + b + c)^2 - 2bc - a^2
 		y.a += t2; // a^2 + 2bc xi
 		Fp2::sub(y.c, y.b, t3); // (a + b + c)^2 - 2bc - a^2 - c^2
-		Fp2::mulXi(y.b, t3); // c^2 xi
+		Fp2::mul_xi(y.b, t3); // c^2 xi
 		y.b += t1; // c^2 xi + 2ab
 		y.c -= t1; // b^2 + 2ac
 	}
@@ -434,7 +434,7 @@ struct Fp6T : public fp::Operator<Fp6T<Fp> > {
 		t1 *= t2;
 		t1 -= be;
 		t1 -= cf;
-		Fp2::mulXi(t1, t1);
+		Fp2::mul_xi(t1, t1);
 
 		Fp2::add(t2, a, b);
 		Fp2::add(t3, e, d);
@@ -449,7 +449,7 @@ struct Fp6T : public fp::Operator<Fp6T<Fp> > {
 		t3 -= cf;
 
 		Fp2::add(z.a, ad, t1);
-		Fp2::mulXi(z.b, cf);
+		Fp2::mul_xi(z.b, cf);
 		z.b += t2;
 		Fp2::add(z.c, t3, be);
 	}
@@ -474,16 +474,16 @@ struct Fp6T : public fp::Operator<Fp6T<Fp> > {
 		Fp2::mul(ac, c, a);
 
 		Fp6T p;
-		Fp2::mulXi(p.a, bc);
+		Fp2::mul_xi(p.a, bc);
 		Fp2::sub(p.a, aa, p.a); // a^2 - bc xi
-		Fp2::mulXi(p.b, cc);
+		Fp2::mul_xi(p.b, cc);
 		p.b -= ab; // c^2 xi - ab
 		Fp2::sub(p.c, bb, ac); // b^2 - ac
 		Fp2 q, t;
 		Fp2::mul(q, p.b, c);
 		Fp2::mul(t, p.c, b);
 		q += t;
-		Fp2::mulXi(q, q);
+		Fp2::mul_xi(q, q);
 		Fp2::mul(t, p.a, a);
 		q += t;
 		Fp2::inv(q, q);
@@ -554,7 +554,7 @@ struct Fp12T : public fp::Operator<Fp12T<Fp> > {
 	static inline void mulVadd(Fp6& z, const Fp6& x, const Fp6& y)
 	{
 		Fp2 t;
-		Fp2::mulXi(t, x.c);
+		Fp2::mul_xi(t, x.c);
 		Fp2::add(z.c, x.b, y.c);
 		Fp2::add(z.b, x.a, y.b);
 		Fp2::add(z.a, t, y.a);
@@ -611,7 +611,7 @@ struct Fp12T : public fp::Operator<Fp12T<Fp> > {
 		Fp6 t0, t1;
 		Fp6::sqr(t0, a);
 		Fp6::sqr(t1, b);
-		Fp2::mulXi(t1.c, t1.c);
+		Fp2::mul_xi(t1.c, t1.c);
 		t0.a -= t1.c;
 		t0.b -= t1.a;
 		t0.c -= t1.b; // t0 = a^2 - b^2v
diff --git a/include/mcl/op.hpp b/include/mcl/op.hpp
index 32ff70c..019466b 100644
--- a/include/mcl/op.hpp
+++ b/include/mcl/op.hpp
@@ -157,7 +157,7 @@ struct Op {
 	void2u fp2_neg;
 	void2u fp2_inv;
 	void2u fp2_sqr;
-	void2u fp2_mulXi;
+	void2u fp2_mul_xi;
 
 	Op()
 		: N(0), bitSize(0)
@@ -181,7 +181,7 @@ struct Op {
 		, fpDbl_sqrPre(0), fpDbl_mulPre(0), fpDbl_mod(0)
 		, xi_a(0)
 		, fp2_add(0), fp2_sub(0), fp2_mul(0), fp2_neg(0)
-		, fp2_sqr(0), fp2_mulXi(0)
+		, fp2_sqr(0), fp2_mul_xi(0)
 	{
 	}
 	~Op()
diff --git a/test/fp_tower_test.cpp b/test/fp_tower_test.cpp
index ca072b7..186b208 100644
--- a/test/fp_tower_test.cpp
+++ b/test/fp_tower_test.cpp
@@ -55,7 +55,7 @@ void testFp2()
 		(1 - 2i)(xi_a + i) = (xi_a + 2) + (1 - 2 xi_a)i
 	*/
 	z = Fp2(1, -2);
-	Fp2::mulXi(z, z);
+	Fp2::mul_xi(z, z);
 	CYBOZU_TEST_EQUAL(z, Fp2(Fp2::getXi_a() + 2, Fp2::getXi_a() * (-2) + 1));
 	z = x * x;
 	sqr(y, x);
@@ -120,11 +120,11 @@ void testFp6sqr(const Fp2& a, const Fp2& b, const Fp2& c, const Fp6& x)
 {
 	Fp2 t;
 	t = b * c * 2;
-	Fp2::mulXi(t, t);
+	Fp2::mul_xi(t, t);
 	t += a * a;
 	CYBOZU_TEST_EQUAL(x.a, t);
 	t = c * c;
-	Fp2::mulXi(t, t);
+	Fp2::mul_xi(t, t);
 	t += a * b * 2;
 	CYBOZU_TEST_EQUAL(x.b, t);
 	t = b * b + a * c * 2;
@@ -322,18 +322,18 @@ void benchFp2()
 	x.a.setStr("4");
 	x.b.setStr("464652165165");
 	y = x * x;
-	double addT, subT, mulT, sqrT, invT, mulXiT;
+	double addT, subT, mulT, sqrT, invT, mul_xiT;
 	CYBOZU_BENCH_T(addT,    Fp2::add, x, x, y);
 	CYBOZU_BENCH_T(subT,    Fp2::sub, x, x, y);
 	CYBOZU_BENCH_T(mulT,    Fp2::mul, x, x, y);
 	CYBOZU_BENCH_T(sqrT,    Fp2::sqr, x, x);
 	CYBOZU_BENCH_T(invT,    Fp2::inv, x, x);
-	CYBOZU_BENCH_T(mulXiT, Fp2::mulXi, x, x);
+	CYBOZU_BENCH_T(mul_xiT, Fp2::mul_xi, x, x);
 //	CYBOZU_BENCH("Fp2::mul_Fp_0", Fp2::mul_Fp_0, x, x, Param::half);
 //	CYBOZU_BENCH("Fp2::mul_Fp_1", Fp2::mul_Fp_1, x, Param::half);
 //	CYBOZU_BENCH("Fp2::divBy2  ", Fp2::divBy2, x, x);
 //	CYBOZU_BENCH("Fp2::divBy4  ", Fp2::divBy4, x, x);
-	printf("add %8.2f|sub %8.2f|mul %8.2f|sqr %8.2f|inv %8.2f|mulXi %8.2f\n", addT, subT, mulT, sqrT, invT, mulXiT);
+	printf("add %8.2f|sub %8.2f|mul %8.2f|sqr %8.2f|inv %8.2f|mul_xi %8.2f\n", addT, subT, mulT, sqrT, invT, mul_xiT);
 }
 
 void test(const char *p, mcl::fp::Mode mode)