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Could someone add an example of a number field with trivial class group, but non-trivial narrow class group? I think I can show that every number field with class number 1 and an infinite group of units has narrow class number 1, but I'm not certain of my proof. This would imply (by Dirichlet's unit theorem) that the only possible such examples are imaginary quadratic number fields.-- Roentgenium111 ( talk) 18:41, 12 May 2009 (UTC) reply

Found a counterexample myself. -- Roentgenium111 ( talk) 11:56, 25 June 2009 (UTC) reply

I'm not sure why RobHar reverted (on October 3, 2010) the corrected definition back to an incorrect definition and said the corrected version was incorrect. I'm going to re-revert but am creating this post in case someone wants to argue for RobHar's version. Barryriedsmith ( talk) 21:08, 19 March 2017 (UTC) reply