Tag Archives: Universal Sequences

Universal binary sequences

Notation. Write Q(A):={aAa is finite,a}. Suppose for the moment that we are given a fixed sequence fα:ω2αa, indexed by some set a of ordinals. Then, for every function h:aω and i<ω, we … Continue reading

Posted in Blog | Tagged , | 3 Comments

Syndetic colorings with applications to S and L

Notation. Write Q(A):={aAa is finite,a}. Definition. An L-space is a regular hereditarily Lindelöf topological space which is not hereditarily separable. Definition. We say that a coloring c:[ω1]2ω is L-syndetic if the following holds. For every uncountable … Continue reading

Posted in Blog, Expository, Open Problems | Tagged , , | 1 Comment