3 months ago paulson 2019-03-19 new material about topology, etc.; also fixes for yesterday's
3 months ago paulson 2019-03-18 new material;' strengthened material; moved proofs out of Function_Topology in order to lessen its dependencies
4 months ago haftmann 2019-01-31 proper congruence rule for image operator
4 months ago paulson 2019-01-22 renamings and new material
5 months ago immler 2019-01-07 split off Homotopy.thy