Base and step now add valid props as invariants.
Removing obsolete update_trans_sys_tsugi in event.
Merge pull request #171 from AdrienChampion/bugfix_kind-valids-as-invariants

Bugfix kind valids as invariants
Merge remote-tracking branch 'upstream/develop' into invGen
Merge remote-tracking branch 'upstream/inv-gen' into invGen
Merge with develop.
Milner testing.
Factorized candidate term generation rules + tuned them.
Two-state / one-state separation in lsd.
Optional trans scanning.
Improved implication pruning and candidate term generation.
Merge pull request #1 from AdrienChampion/milner

Merging benchmarking branch (for milner).
Merge pull request #174 from AdrienChampion/invGen

Inv gen