Better conversion

Given an implicit conversion C1 that converts from a type S to a type T1, and an implicit conversion C2 that converts from a type S to a type T2, the better conversion of the two conversions is determined as follows: If T1 and T2 are the same type, neither conversion is better. If S is T1, C1 is the better conversion. If S is T2, C2 is the better conversion. If an implicit conversion from T1 to T2 exists, and no implicit conversion from T2 to T1 exists, C1 is the better conversion. If an implicit conversion from T2 to T1 exists, and no implicit conversion from T1 to T2 exists, C2 is the better conversion. If T1 is sbyte and T2 is byte, ushort, uint, or ulong, C1 is the better conversion. If T2 is sbyte and T1 is byte, ushort, uint, or ulong, C2 is the better conversion. If T1 is short and T2 is ushort, uint, or ulong, C1 is the better conversion. If T2 is short and T1 is ushort, uint, or ulong, C2 is the better conversion. If T1 is int and T2 is uint, or ulong, C1 is the better conversion. If T2 is int and T1 is uint, or ulong, C2 is the better conversion. If T1 is long and T2 is ulong, C1 is the better conversion. If T2 is long and T1 is ulong, C2 is the better conversion. Otherwise, neither conversion is better.
If an implicit conversion C1 is defined by these rules to be a better conversion than an implicit conversion C2, then it is also the case that C2 is a worse conversion than C1.