 The first uncountable ordinal with the order topology is an example of a sequentially compact topological space that is not compact.The product of formula_1 copies of the closed unit interval is an example of a compact space that is not sequentially compact.A topological space "X" is said to be limit point compact if every infinite subset of "X" has a limit point in "X", and countably compact if every countable open cover has a finite subcover.