Adding a term to the search query should replace any broader/narrower terms

[arildm]

It is pointless to have both a broader and a narrower term in the search query, e.g. combining "Homosexuella" AND "Unga lesbiska".

If I already have "Homosexuella" in my search query, and I want to add "Unga lesbiska", the option should perhaps say something like "Sök efter 'Unga lesbiska' – ersätt det bredare ämnet 'Homosexuella'". Well, that's too long for a menu option, but yeah, it should be clear somehow that the broader term will be replaced.