diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..60d2378
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,15 @@
+language: swift
+os: osx
+xcode_project: SwiftBitset
+xcode_scheme: SwiftBitset-Package
+osx_image:
+- xcode9.4
+- xcode10
+before_install:
+- brew update
+script:
+- swift package generate-xcodeproj
+- set -o pipefail && xcodebuild -scheme SwiftBitset-Package -enableCodeCoverage YES clean build test
+- swift build
+- swift test
+- swift test -Xswiftc -Ounchecked -s BitsetTests.BitsetTests/testForEachPerformance
diff --git a/Package.swift b/Package.swift
index d27a3d7..eb74667 100644
--- a/Package.swift
+++ b/Package.swift
@@ -7,8 +7,15 @@ let package = Package(
         .library(name: "Bitset", targets: ["Bitset"]),
         .library(name: "BitsetDynamic", type: .dynamic , targets: ["Bitset"]),
     ],
+    dependencies: [],
     targets: [
-        .target(name: "Bitset", dependencies: []),
-        .testTarget(name: "BitsetTests", dependencies: ["Bitset"])
+    .target(
+        name: "Bitset",
+        dependencies: []
+    ),
+    .testTarget(
+        name: "BitsetTests",
+        dependencies:["Bitset"]
+    )
     ]
 )
diff --git a/README.md b/README.md
index 6fa13be..0124022 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 <a href="https://developer.apple.com/swift"><img src="https://img.shields.io/badge/Swift4-compatible-green.svg?style=flat" alt="Swift 4 compatible" /></a>
 <a href="https://github.com/apple/swift-package-manager"><img src="https://img.shields.io/badge/Swift%20Package%20Manager-compatible-brightgreen.svg"/></a>
-
+[![Build Status](https://travis-ci.org/lemire/SwiftBitset.svg?branch=master)](https://travis-ci.org/lemire/SwiftBitset)
 
 A bitset class in Swift for fast and concise set operations over integers. Works under both Linux and MacOS.
 It is engineered to be really fast, on par with portable C/C++ implementations.
@@ -14,7 +14,7 @@ $ git clone https://github.com/lemire/SwiftBitsetBenchmark.git
 $ cd SwiftBitsetBenchmark
 $ swift build  -Xcc -march=native  --configuration release
 
-$(swift build   --configuration release --show-bin-path)/SwiftBitsetBenchmark
+$ $(swift build   --configuration release --show-bin-path)/SwiftBitsetBenchmark
 testAddPerformance  10.693318  ms
 testIndexSetAddPerformance  231.737616  ms
 
@@ -101,11 +101,11 @@ for i in b1 {
 b1.remove(4) // can remove values
 let d1 = b1 & b2;// intersection
 let d2 = b1 | b2;// union
-let d3 = b1 &^ b2;// difference
+let d3 = b1 - b2;// difference
 let d4 = b1 ^ b2;// symmetric difference
 b1 &= b2;// inplace intersection
 b1 |= b2;// inplace union
-b1 &^= b2;// inplace difference
+b1 -= b2;// inplace difference
 b1 ^= b2;// inplace symmetric difference
 ```
 
@@ -143,7 +143,7 @@ $ swift -I .build/release -L .build/release -lBitsetDynamic
 ```bash
 $ swift package generate-xcodeproj
 generated: ./Bitset.xcodeproj
-$ open ./Bitset.xcodeproj
+$ open ./SwiftBitset.xcodeproj
 ```
 
 ## Licensing
diff --git a/Sources/Bitset/Bitset.swift b/Sources/Bitset/Bitset.swift
index bffd4d6..e9710c3 100644
--- a/Sources/Bitset/Bitset.swift
+++ b/Sources/Bitset/Bitset.swift
@@ -1,6 +1,4 @@
 
-infix operator &^;// andNot
-infix operator &^=;// andNot
 
 private extension Int64 {
     func toUInt64() -> UInt64 { return UInt64(bitPattern:self) }
@@ -83,15 +81,16 @@ public final class Bitset: Sequence, Equatable, CustomStringConvertible,
     lhs.union(rhs)
   }
 
+
   // difference between two bitsets, producing a new bitset
-  public static func &^ (lhs: Bitset, rhs: Bitset) -> Bitset {
+  public static func - (lhs: Bitset, rhs: Bitset) -> Bitset {
     let mycopy = Bitset(lhs)
     mycopy.difference(rhs)
     return mycopy
   }
 
   // inplace difference between two bitsets
-  public static func &^= (lhs: Bitset, rhs: Bitset) {
+  public static func -= (lhs: Bitset, rhs: Bitset) {
     lhs.difference(rhs)
   }
 
diff --git a/Tests/BitsetTests/BitsetTests.swift b/Tests/BitsetTests/BitsetTests.swift
index 1e04b1d..f1618c1 100644
--- a/Tests/BitsetTests/BitsetTests.swift
+++ b/Tests/BitsetTests/BitsetTests.swift
@@ -193,7 +193,7 @@ class BitsetTests: XCTestCase {
     let B1 = Bitset(b1)
     let B2 = Bitset(b2)
 
-    b2 &^= b1
+    b2 -= b1
     B2.difference(B1)
     XCTAssertEqual(B2, b2, "Bad operator")
   }
@@ -203,7 +203,7 @@ class BitsetTests: XCTestCase {
     let B1 = Bitset(b1)
     let B2 = Bitset(b2)
 
-    let b3 = b2 &^ b1
+    let b3 = b2 - b1
     B2.difference(B1)
     XCTAssertEqual(B2, b3, "Bad operator")
   }
@@ -239,11 +239,11 @@ class BitsetTests: XCTestCase {
      // will print 1 4 10 1000 10000
     _ = b1 & b2;// intersection
     _ = b1 | b2;// union
-    _ = b1 &^ b2;// difference
+    _ = b1 - b2;// difference
     _ = b1 ^ b2;// symmetric difference
     b1 &= b2;// inplace intersection
     b1 |= b2;// inplace union
-    b1 &^= b2;// inplace difference
+    b1 -= b2;// inplace difference
     b1 ^= b2;// inplace symmetric difference
   }
 
@@ -271,7 +271,7 @@ class BitsetTests: XCTestCase {
 
 #if os(Linux)
 extension BitsetTests {
-  static var allTests: [(String, (BitsetTests) -> Void throws->Void)] {
+  static var allTests: [(String, (BitsetTests) -> () throws->())] {
     return [
       ("testUnion", testUnion),
       ("testIterator", testIterator),