Equality is highly overrated

Equality only exist in integer math. We use this integer equality to measure identity not equality. This is one quart of milk. This is another quart of milk. Together they are two quarts of milk.

All things are different. There is always a distinct variable that will show difference in objects that would normally pass an identity proof, symmetry proof. There is always some level of variability between two seemingly identical objects.

Seemingly identical objects measured as Real Numbers, will always show difference. Minutia is required in identifying objects measured in Real Numbers. One quart of milk will never equal another quart of milk. Quart (a) != Quart (b). Two quarts of milk cannot weigh the same. Two quarts of milk cannot occupy the same space. two quarts of milk will have different volumes because of rates of spoilage. The two quarts of milk will have different temperatures. The two quarts of milk will have different histories. The two quarts of milk have different values based on location.   

All of those variables are required to make a quart of milk. You cannot have a quart of milk without a rate of spoilage. Even frozen there is a point in time when the milk breaks down or is no longer functional as the abstraction milk. This is true for all real objects and their cumulative abstractions.