Description:
A paratopological group G is saturated if the in-
verse U−1 of each non-empty set U ½ G has non-empty interior. It
is shown that a [first-countable] paratopological group H is a closed
subgroup of a saturated (totally bounded) [abelian] paratopological
group if and only if H admits a continuous bijective homomorphism
onto a (totally bounded) [abelian] topological group G [such that
for each neighborhood U ½ H of the unit e there is a closed subset
F ½ G with e 2 h−1(F) ½ U]. As an application we construct a
paratopological group whose character exceeds its ¼-weight as well
as the character of its group reflexion. Also we present several ex-
amples of (para)topological groups which are subgroups of totally
bounded paratopological groups but fail to be subgroups of regular
totally bounded paratopological groups.