1

Ultrafilters on a discrete set with two binary operations

Year:
1991
Language:
english
File:
PDF, 198 KB
english, 1991
2

Free groups in βN which miss the minimal ideal

Year:
1988
Language:
english
File:
PDF, 163 KB
english, 1988
3

Points very close to the smallest ideal of βS

Year:
1994
Language:
english
File:
PDF, 270 KB
english, 1994
4

Multi-dimensional Ramsey theorems — An example

Year:
1992
Language:
english
File:
PDF, 110 KB
english, 1992