Continuous homomorphisms of R onto a compact group
Douglas Bridges, Matthew Hendtlass · Mathematical logic quarterly · 2010
It is shown within Bishop's constructive mathematics that, under one extra, classically automatic, hypothesis, a continuous homomorphism from R onto a compact metric abelian group is periodic, but that the existence of the minimum value of the period is not derivable (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)