diff --git a/include/cuinterval/arithmetic/basic.cuh b/include/cuinterval/arithmetic/basic.cuh
index cf7e8dc..643a749 100644
--- a/include/cuinterval/arithmetic/basic.cuh
+++ b/include/cuinterval/arithmetic/basic.cuh
@@ -919,25 +919,25 @@ inline constexpr __device__ interval<T> rootn(interval<T> x, std::integral auto
         return x;
     }
 
-    auto rootn_pos_n = [](interval<T> x, std::integral auto n) -> interval<T> {
-        if (n == 0) {
+    auto rootn_pos_n = [](interval<T> y, std::integral auto m) -> interval<T> {
+        if (m == 0) {
             return empty<T>();
-        } else if (n == 1) {
-            return x;
-        } else if (n == 2) {
-            return sqrt(x);
+        } else if (m == 1) {
+            return y;
+        } else if (m == 2) {
+            return sqrt(y);
         } else {
-            bool is_odd = n % 2;
+            bool is_odd = m % 2;
             interval<T> domain { is_odd ? intrinsic::neg_inf<T>() : static_cast<T>(0),
                                  intrinsic::pos_inf<T>() };
 
-            x = intersection(x, domain);
-            if (empty(x)) {
+            y = intersection(y, domain);
+            if (empty(y)) {
                 return empty<T>();
             }
 
-            return { intrinsic::next_after(pow(inf(x), 1.0 / n), domain.lb),
-                     intrinsic::next_after(pow(sup(x), 1.0 / n), domain.ub) };
+            return { intrinsic::next_after(pow(inf(y), 1.0 / m), domain.lb),
+                     intrinsic::next_after(pow(sup(y), 1.0 / m), domain.ub) };
         }
     };
 
diff --git a/include/cuinterval/interval.h b/include/cuinterval/interval.h
index c350102..908172b 100644
--- a/include/cuinterval/interval.h
+++ b/include/cuinterval/interval.h
@@ -18,7 +18,8 @@ constexpr bool operator==(interval<T> lhs, interval<T> rhs)
 {
     auto empty = [](interval<T> x) { return !(x.lb <= x.ub); };
 
-    return (empty(lhs) && empty(rhs)) || lhs.lb == rhs.lb && lhs.ub == rhs.ub;
+
+    return (empty(lhs) && empty(rhs)) || (lhs.lb == rhs.lb && lhs.ub == rhs.ub);
 }
 
 template<typename T>
diff --git a/tests/tests.cpp b/tests/tests.cpp
index 95cebf2..9010ca8 100644
--- a/tests/tests.cpp
+++ b/tests/tests.cpp
@@ -9,7 +9,7 @@
 #include <cstddef>
 #include <cstdio>
 
-int main(int argc, char *argv[])
+int main()
 {
     CUDA_CHECK(cudaSetDevice(0));
 
diff --git a/tests/tests.h b/tests/tests.h
index 189c3cf..a06e7da 100644
--- a/tests/tests.h
+++ b/tests/tests.h
@@ -31,7 +31,7 @@ bool check_within_ulps(T x, T y, std::size_t n, T direction)
         return true;
     }
 
-    for (int i = 0; i < n; ++i) {
+    for (auto i = 0u; i < n; ++i) {
         y = std::nextafter(y, direction);
 
         if (x == y) {
diff --git a/tests/tests_loop.cu b/tests/tests_loop.cu
index 2cd0218..dee02d0 100644
--- a/tests/tests_loop.cu
+++ b/tests/tests_loop.cu
@@ -94,8 +94,6 @@ std::vector<interval<double>> compute_pi_approximation(cudaStream_t stream)
     auto tr_last      = thrust::make_transform_iterator(seq_last, to_interval_fn());
     auto pi_rcp_first = thrust::make_transform_iterator(tr_first, pi_recip_fn());
     auto pi_rcp_last  = thrust::make_transform_iterator(tr_last, pi_recip_fn());
-    auto pi_pow_first = thrust::make_transform_iterator(tr_first, pi_pow_fn());
-    auto pi_pow_last  = thrust::make_transform_iterator(tr_last, pi_pow_fn());
     auto pi_inv_first = thrust::make_transform_iterator(tr_first, pi_inv_fn());
     auto pi_inv_last  = thrust::make_transform_iterator(tr_last, pi_inv_fn());