src/HOL/Library/Cancellation.thy
17 months ago nipkow 2018-01-10 ran isabelle update_op on all sources
2017-05-10 blanchet 2017-05-10 tuning
2017-02-16 fleury 2017-02-16 don't activate simproc on cancel_comm_monoid_add
2017-02-14 fleury 2017-02-14 cancellation simprocs generalising the multiset simprocs