12 months ago nipkow 2018-06-07 utilize 'flip'
17 months ago haftmann 2018-01-13 restored naming of lemmas after corresponding constants
17 months ago nipkow 2018-01-10 ran isabelle update_op on all sources
20 months ago haftmann 2017-10-30 tuned some proofs and added some lemmas
22 months ago Andreas Lochbihler 2017-08-30 add type of unordered pairs