Apply feedbacks from Alain.
Explain what we have our own solver.
Uniformize the vocabulary.
Polish vocabulary.
Simplify grammar.
Better transition.
Add tikz style: box.
Introduce universe of realdoms.
Remove a pagebreak.
Remove some \strong.
Postpone the @is clause in perspectives.
Fix a bad \ref.
Simplify \pred() and RAC presentation.
Apply feedbacks from Alain.