public bool isLike(IPair <T> b)
{
return(b.NotNull() &&
(_p0.Equals(b.p0) && _p1.Equals(b.p1)) || (_p0.Equals(b.p1) && _p1.Equals(b.p0)));
}
public bool isExact(IPair <T> b)
{
return(b.NotNull() && _p0.Equals(b.p0) && _p1.Equals(b.p1));
}