Claude Fable 5.1 on Tricky grid 3

5 given 5 filled correctly 53 wrong, with the right digit 3 left empty

The end of its reply

}. r1c5,r3c5={3,5}; r1c5 can't be 5 → 3. ✓.
Recheck r6c4=1 and r4c5=9: r6c4∈{1,9}; row6 has 9 at r6c7 → 1 ✓. r4c5=9 since 9 must be r4c5 or r6c4 ✓ (box5 missing 1,2,5,6,7,9; 9 positions: r4c5, r5c5, r6c4, r6c5, r5c6,r6c6; r5 row has 9; col6 has 9 at r7c6. so r4c5 or r6c4 ✓).
Recheck r7c6=9: r7c6 ∈ col6 avail {3,4,5,7,9} ∩ row7 missing {1,8,9} → 9 ✓. r7c3=3 ✓. r7c7=1, r7c5=8 ✓.
r9c9=6, r9c7=8 ✓. r8c1=2 ✓. r9c1=1, r9c2=9, r9c3=4 ✓.
r9c6=3: r9c6∈{3,7}, r8c6∈{4,5}, col6 needs 3,4,5,7 at r5,r6,r8,r9; box5 cells r5c6,r6c6 ∈{5,7} (box5 missing 1,2,5,6,7,9 ∩ col6 avail) → 3,4 must be r8c6,r9c6: r8c6=4, r9c6=3, r9c5=7 ✓. r8c4,r8c5={1,5} ✓ → r8c4=5, r8c5=1 after r6c4=1 ✓.
Col5 for r1,r3: {3,5} ✓. r2c5=4 ✓ (4 in box2 only possible at r2c5? r1 row has 4, r3 row has 4 ✓).
r5c7=4: box6 4 positions: r4 row? row4 has 4. r6 row? r6c1=4 came later... row6 could have 4 in box6? r6c8, r6c9: col8 has 4, col9 has 4. So yes r5c7=4 ✓ (r5c8,r5c9 col has 4).
r3c9=9 ✓ (col9 9 only at r3 since r1c4=9, r4c5=9? row4 has 9, r5 has 9, r6 has 9, r8 has 9). ✓
r6c1=4 ✓. r4c2=1 ✓.
r2c3=5: box1 5 positions: r1c3 (row1 has 5), r2c3, r3c1 (row3 has 5 at r3c5 ✓). ✓
r3c1=6: box1 6: r1 row has 6; r2c3=5; r3c1 ✓. So col1: r4,r5 ∈ {3,5}; r5∈{5,6} → 5, r4c1=3 ✓.
Row5: 5 8 9 3 _ _ 4 _ _ missing 1,2,6,7: r5c6∈{5,7}→7, r6c6=5 ✓.
Now r2c2∈{2,3}, r3c2∈{3,7}, r1c3∈{2,7}. Box1 needs 2,3,7 in those three.
Case r2c2=2: r1c3=7, r3c2=3. Row3: 6 3 1 8 5 2 _ 4 9 → r3c7=7. Row2: 9 2 5 7 4 1 _ _ 8 → {3,6}. Row1: 8 4 7 9 3 6 5 _ _ → {1,2}. Col8 (need 1,3,6,7 at r1,r2,r4,r5): r1c8=1, r2c8∈{3,6}, r1c9=2. r2c7: col7 remaining after 5,_,7,_,4,9,1,_,8: need 2,3,6 at r2,r4,r8. r8c7∈{3,7}→3. r2c7∈{3,6}→6, r2c8=3. r4c7=2. r8c9=7. Row4: 3 1 _ 4 9 8 2 _ _ missing 5,6,7; r4c3∈{6,7}, r4c8∈{6,7}, r4c9∈{5,7}. Col8 remaining 6,7 for r4,r5. Row5: 5 8 9 3 _ 7 4 _ _ missing 1,2,6: r5c8=6, so r4c8=7, r5c5∈{2}? r5c5,r5c9 = {1,2}; r5c9 col9 → 1 or 2; col9 needs 1,3,5,7 → r5c9=1, r5c5=2, r6c5=6. r4c3=6, r4c9=5. Row6: 4 _ _ 1 6 5 9 8 _ missing 2,3,7: r6c2 col2 (4,2,3,1,8,_,5,6,9)→7, r6c3=2? col3: 7,5,1,6,9,_,3,8,4 → 2 ✓. r6c9=3 ✓ col9: 2,8,9,5,1,3,4,7,6 ✓.

Solution:
R1: 8 4 7 9 3 6 5 1 2
R2: 9 2 5 7 4 1 6 3 8
R3: 6 3 1 8 5 2 7 4 9
R4: 3 1 6 4 9 8 2 7 5
R5: 5 8 9 3 2 7 4 6 1
R6: 4 7 2 1 6 5 9 8 3
R7: 7 5 3 6 8 9 1 2 4
R8: 2 6 8 5 1 4 3 9 7
R9: 1 9 4 2 7 3 8 5 6

Check columns: C1 8,9,6,3,5,4,7,2,1 ✓. C2 4,2,3,1,8,7,5,6,9 ✓. C3 7,5,1,6,9,2,3,8,4 ✓. C4 9,7,8,4,3,1,6,5,2 ✓. C5 3,4,5,9,2,6,8,1,7 ✓. C6 6,1,2,8,7,5,9,4,3 ✓. C7 5,6,7,2,4,9,1,3,8 ✓. C8 1,3,4,7,6,8,2,9,5 ✓. C9 2,8,9,5,1,3,4,7,6 ✓. Boxes: box1 847/925/631 ✓; box2 936/741/852 ✓; box3 512/638/749 ✓; box4 316/589/472 ✓; box5 498/327/165 ✓; box6 275/461/983 ✓; box7 753/268/194 ✓; box8 689/514/273 ✓; box9 124/397/856 ✓. Givens match.Correcting my earlier slip — I re-derived the solution carefully by hand and verified every row, column, and box:

<grid>
847936512
925741638
631852749
316498275
589327461
472165983
753689124
268514397
194273856
</grid>

<confidence>99</confidence>

Grid tricky-2 of set v1, 24 givens. Puzzle as one line: .4...65..9....1..8..1..2.4....4.8....893...........9..75.6...24.68.........2...5.