2. In the solution are all 5 letters of NEBEL
3. No letter touches an adjacent letter of the complete alphabet on an edge or corner. Same letters also don't touch each other
4. The field index numbers of the letters of LEBEN are rising within the word (but not necessarily directly following each other)
5. In every row and every column is one vowel
6. Only one of the two following statements is true: In field 1 is no letter of LATERNE. In field 9 is no letter of ST MARTIN
7. Only one of the two following statements is true: In field 5 is no letter of PFERD. In field 6 is no letter of BETTLER
Solution code: row after row from left to right