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Packing Countably Many Branchings with Prescribed Root‐Sets in Infinite Digraphs
Author(s) -
Joó Attila
Publication year - 2018
Publication title -
journal of graph theory
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 54
eISSN - 1097-0118
pISSN - 0364-9024
DOI - 10.1002/jgt.22145
Subject(s) - digraph , mathematics , disjoint sets , combinatorics , multiset , path (computing) , enhanced data rates for gsm evolution , root (linguistics) , set (abstract data type) , discrete mathematics , computer science , telecommunications , linguistics , philosophy , programming language
Abstract We generalize an unpublished result of C. Thomassen. Let D = ( V , A ) be a digraph and let{ V i } i ∈ Nbe a multiset of subsets of V in such a way that any backward‐infinite path in D meets all the sets V i . We show that if all v ∈ V is simultaneously reachable from the sets V i by edge‐disjoint paths, then there exists a system of edge‐disjoint spanning branchings{ B i } i ∈ Nin D where the root‐set of B i is V i .