Case C-13/20: Judgment of the Court (Fifth Chamber) of 6 October 2021 (request for a preliminary ruling from the Cour d’appel de Bruxelles — Belgium) — Top System SA v Belgian State (Reference for a preliminary ruling — Copyright and related rights — Legal protection of computer programs — Directive 91/250/EEC — Article 5 — Exceptions to the restricted acts — Acts necessary to enable the lawful purchaser to correct errors — Concept — Article 6 — Decompilation — Conditions)