This approach eased development of X-Checker, and for
the most part our hypothesis about the equivalence of the
desktop and phone version of Windows was correct. However,
we found (and reported to Microsoft) a case where
the desktop and phone versions diverged in their semantics.
In particular, the public property CurrencyDecimalDigits
of the class System.Globalization.NumberFormatInfo is
required to be a read-only field according to MSDN documentation.
While the read-only property holds in the desktop
version, the property is mutable in the Windows Phone version.
We also found, using differential testing against Android, a
case where both the desktop and phone version of Windows
incorrectly implement the documented semantics for a
given property, while Android’s implementation followed Microsoft’s
documentation. In particular, the property WebName of
System.Text.Encoding.BigEndianUnicode must have the