Jech–Kunen tree

In mathematics, a Jech–Kunen tree is a tree of power ω₁ and height ω₁ in which the number of branches is greater than ω₁ and less than 2^ω₁. They are named after Thomas Jech (1971) who found the first example, and Kenneth Kunen (1975) who related them to the cardinalities of compact spaces.