Unlike in classic mathematics, the cardinality of, for example, {a,b,c,...} (notated as {|a,b,c,...|} is endlessly changing (
classic mathematics can't deal with non fixed cardinalities).
Yet it can be compared with other cardinal numbers, for example:
{|a,b,c,...|} < {|a,b,c,...|+1} by 1
{|a,b,c,...|} < {|a,b,c,...|*|a,b,c,...|} = {|a,b,c,...|*2} twice (in this case the notion of proportion is used).
etc.
Also {|a,b,c|} < {|a,b,c,...|} but the difference is non fixed.
Generally we have the following types of cardinality:
{| |} is the cardinality of NO
thing (logically defined as contradiction). (
classic mathematics can't deal with this notion)
|{ }| is the cardinality of YES
thing (logically defined as tautology). (
classic mathematics can't deal with this notion)
{|a,b,c|} is an example of a fixed cardinality (logically defined as ~contradiction AND ~tautology).
{|a,b,c,...|} is an example of a non fixed (endlessly changing) cardinality (logically defined as ~contradiction AND ~tautology). (
classic mathematics can't deal with this notion)
The notion of proper subset, in case non fixed cardinality, is irrelevant. (
classic mathematics can't deal with this notion)
thing in itself is the foundation of these types (including logic), which is not limited by them (it is not defined by its expressions, as illustrated, for example, by
this logical structure). (
classic mathematics can't deal with this notion)