anchor.diff:          Assert.IsTrue(z1.Equals(z1))
           Assert.IsTrue(z2.Equals(z2))
           Assert.IsTrue(z3.Equals(z3))
  -#if MONO // see https://bugzilla.xamarin.com/show_bug.cgi?id=22591
  +#if CROSS_PLATFORM_COMPILER // see https://bugzilla.xamarin.com/show_bug.cgi?id=22591
   #else
           Assert.IsTrue(z4.Equals(z4))
   #endif
  
positive.code:         Assert.AreEqual(+bigPositiveA,bigPositiveA)
          Assert.AreEqual(+bigNegativeA,bigNegativeA)
          Assert.AreEqual(+0I,0I)
  #if MONO // see https://bugzilla.xamarin.com/show_bug.cgi?id=22591
  #else
          Assert.AreEqual(+BigInteger(),0I)
  #endif
  
negative.code:         Assert.IsTrue( b.Equals(c) ); Assert.IsTrue( c.Equals(b) )
          Assert.IsTrue( c.Equals(a) ); Assert.IsTrue( a.Equals(c) )
          Assert.IsTrue( z1.Equals(z2) ); Assert.IsTrue( z2.Equals(z3) )
  #if CROSS_PLATFORM_COMPILER // see https://bugzilla.xamarin.com/show_bug.cgi?id=22591
  #else
          Assert.IsTrue( z3.Equals(z4) ); Assert.IsTrue( z4.Equals(z1) )
  #endif
  