#### Filter Results:

#### Publication Year

1996

2005

#### Publication Type

#### Co-author

#### Publication Venue

Learn More

We investigate the strength of set existence axioms needed for separable Banach space theory. We show that a very strong axiom, Π 1 1 comprehension , is needed to prove such basic facts as the existence of the weak-* closure of any norm-closed subspace of 1 = c * 0. This is in contrast to earlier work [6, 4, 7, 23, 22] in which theorems of separable Banach… (More)

investigating the strength of set existence axioms needed for separable Banach space theory. We show that the separation theorem for open convex sets is equivalent to WKL 0 over RCA 0. We show that the separation theorem for separably closed convex sets is equivalent to ACA 0 over RCA 0. Our strategy for proving these geometrical Hahn–Banach theorems is to… (More)

- Martin Keen, Oscar Adinolfi, Sarah Hemmings, Andrew Humphreys, Hanumanth Kanthi, Alasdair Nottingham
- 2005

- ‹
- 1
- ›