No Universal Equality

build.sbt

@@ -33,6 +33,7 @@ val SharedSettings = Seq(
   libraryDependencies ++= Seq(
     "com.github.scalaprops" %%% "scalaprops" % ScalaPropsVersion % "test,it",
     "com.github.scalaprops" %%% "scalaprops-scalazlaws" % ScalaPropsVersion % "test,it",
+    "org.scalaz" %%% "scalaz-core" % "7.2.27",
   ),
   libraryDependencies ++= Seq(
     "biz.enef" %%% "slogging" % SloggingVersion,

re/shared/src/it/scala/pl/writeonly/re/shared/CalculatorIT.scala

@@ -1,22 +1,23 @@
 package pl.writeonly.re.shared
 
 import scalaprops.{Property, Scalaprops}
+import scalaz.Scalaz._
 
 object CalculatorIT extends Scalaprops {
   val calculator = new Calculator()
 
   val addition: (Int, Int) => Int = (x, y) => calculator.add(x, y)
   val additionTest = Property.forAll { (a: Int, b: Int) =>
-    addition(a, b) == a + b
+    addition(a, b) === a + b
   }
 
   val multiplication: (Int, Int) => Int = (x, y) => calculator.mul(x, y)
   val multiplicationTest = Property.forAll { (a: Int, b: Int) =>
-    multiplication(a, b) == a * b
+    multiplication(a, b) === a * b
   }
 
   val lessOrEqual: (Int, Int) => Boolean = (x, y) => calculator.leq(x, y)
   val lessOrEqualTest = Property.forAll { (a: Int, b: Int) =>
-    lessOrEqual(a, b) == (a <= b)
+    lessOrEqual(a, b) === (a <= b)
   }
 }