The isomorphism relation on countable torsion free abelian groups
Tom 175 / 2002
Fundamenta Mathematicae 175 (2002), 241-257
MSC: Primary 03E15.
DOI: 10.4064/fm175-3-2
Streszczenie
The isomorphism relation on countable torsion free abelian groups is non-Borel.
