Revision as of 07:27, 18 October 2009 edit Kompik (talk \| contribs) Extended confirmed users 8,446 edits →References ← Previous edit		Revision as of 08:01, 18 October 2009 edit undo Kompik (talk \| contribs) Extended confirmed users 8,446 edits closed under subsequences -> initial segments Next edit →
Line 1: In [[descriptive set theory]], a '''tree''' on a set <math>X</math> is a set of finite sequences of elements of <math>X</math> that is closed ~~under~~initial ~~subsequences~~segments. More formally, it is a subset <math>T</math> of <math>X^{<\omega}</math>, such that if

Tree (descriptive set theory): Difference between revisions