The pool without a licence

At a holiday home in a protected area, a swimming pool sprang up in a few weeks. Nobody knows where the licence is, but everybody knows who should have it. Four people and one piece of evidence: one person per row, one per column. Whoever is left alone with it in the same room is the one you're looking for.

Suspects

• Adosinda, the neighbour: She lives in the house next door and watched the pool grow day by day.
• Belchior, the pool builder: He built the pool in three weeks. The licence has been in the works for three years.
• Cremilde, the council inspector: She came to inspect the works and stayed for tea.
• Durval, the gardener: He looks after the garden and the protected plants, which are now under the pool.