@Micner : En effet, on peut le voir ainsi
@Jeeg : No guessing if you know the good tricks ;) Here, you can use edge-logic regarding how R1 affects R3, or how R23 affects R21. For example, you can eliminate the positions where the 6 from R1 would induce a 4 or less at the end of R3; you can eliminate the positions where the 5 from R23 would induce more than a 2 at the beginning of R21. Hope that will help ;)
On dirait un peu un nuage aussi... Merci
@Micner : En effet, on peut le voir ainsi
@Jeeg : No guessing if you know the good tricks ;) Here, you can use edge-logic regarding how R1 affects R3, or how R23 affects R21. For example, you can eliminate the positions where the 6 from R1 would induce a 4 or less at the end of R3; you can eliminate the positions where the 5 from R23 would induce more than a 2 at the beginning of R21. Hope that will help ;)