Constraint Lab

Clues

1. There are five houses. fixed
2. The Englishman lives in the red house.
3. The Spaniard owns the dog.
4. Coffee is drunk in the green house.
5. The Ukrainian drinks tea.
6. The green house is immediately to the right of the ivory house.
7. The Old Gold smoker owns snails.
8. Kools are smoked in the yellow house.
9. Milk is drunk in the middle house.
10. The Norwegian lives in the first house.
11. Chesterfields are smoked next to the house with the fox.
12. Kools are smoked next to the house with the horse.
13. The Lucky Strike smoker drinks orange juice.
14. The Japanese smokes Parliaments.
15. The Norwegian lives next to the blue house.

Combinations remaining

…

Request & response

Column legend — each column A1…E5 is one property; its value is the house sequence (1–5) that property occupies.

A Nationality A1 Englishman · A2 Spaniard · A3 Ukrainian · A4 Norwegian · A5 Japanese

B Color B1 Red · B2 Green · B3 Ivory · B4 Yellow · B5 Blue

C Drink C1 Coffee · C2 Tea · C3 Milk · C4 Orange juice · C5 Water

D Smoke D1 Old Gold · D2 Kools · D3 Chesterfields · D4 Lucky Strike · D5 Parliaments

E Pet E1 Dog · E2 Snails · E3 Fox · E4 Horse · E5 Zebra

The browser posts the selected clue indices to the FE proxy; the FE forwards them to the secured BE, which builds the SQL (server-side) and returns the count. The browser never sends SQL. The BE works in A1…E5 house numbers — labels are derived from the legend.

Clues

Combinations remaining

Request & response

Request — logic the BE evaluated

Response — JSON (BE → FE proxy → browser)

First arrangements — up to 3 sample solutions, rebuilt from A1…E5 + legend