For a Banach space
, we show how the existence of a norm-one element
in
and a norm-one continuous bilinear mapping
satisfying
for all
in
, together with some more intrinsic
conditions, can be utilized to characterize
as a member of some relevant
subclass of the class of Banach spaces.
1991 Mathematics Subject Classification: 46C15, 46K70, 46B08, 17C65.