Human rights — Freedom of thought, conscience and religion — Article 9 of European Convention on Human Rights, 1950 — Compulsory mixed gender swimming lessons in primary schools — Refusal by competent authorities to grant applicants’ daughters exemption from mixed swimming lessons — Whether contested measure interfering with exercise of applicants’ right to freedom of religion — Whether interference justified — Whether having legal basis — Whether pursuing legitimate aim — Whether necessary in a democratic society — Whether proportionate to aims pursued by national authorities — Article 2 of Protocol No 1 lex specialis in relation to Article 9 of Convention — Inapplicability of Article 2 of Protocol No 2 — Reading of Convention as a whole — Whether Switzerland violating Article 9 of European Convention on Human Rights, 1950