In this paper, we introduce two notions of closure operators in the category
of Cauchy spaces which satisfy (weak) hereditariness, productivity and
idempotency, and we characterize each of Ti, i = 0, 1, 2 cauchy spaces by
using these closure operators as well as show each of these subcategories
are isomorphic. Furthermore, we characterize the irreducible Cauchy spaces
and examine the relationship among each of irreducible, connected Cauchy
spaces. Finally, we present Urysohn?s lemma and Tietze extension theorem for
Cauchy spaces.