8..|93.|..2    846|937|152
..9|...|.4.    319|625|847
7.2|1..|96.    752|184|963
---+---+--+    ---+---+--+
2..|...|.9.    285|713|694
.6.|...|.7.    463|859|271
.7.|..6|..5    971|246|385
---+---+---    ---+---+---
.27|..8|4.6    127|598|436
.3.|...|5..    638|471|529
5..|.62|..8    594|362|718

1..4    1234
.3..    4321
..1.    3412
...3    2143

.4.. ...2 .... 32..    2431 1342 4123 3214

ERROR! Not a square at sudoku.pl line 71.

1..4
.3..
..1.
..2

21..    2143
....    3412
..3.    1234
.3.1    4321

. .|. . .    3 4|5 1 2
   | ---        | --- 
. 1|.|.|.    5 1|4|2|3
 --|-- --     --|-- --
.|.|. . 5    2|3|1 4 5
-- --- --    -- --- --
4 . .|.|.    4 5 2|3|1
 -------      ------- 
.|2 . . 4    1|2 3 5 4

.P.|K.R|I.D    WPE|KAR|IBD
D..|B..|..R    DIA|BWP|KER
.B.|E..|PA.    RBK|EID|PAW
---+---+---    ---+---+---
P..|.KW|A.B    PER|IKW|ADB
...|...|RK.    IWB|DPA|RKE
.AD|...|...    KAD|RBE|WPI
---+---+---    ---+---+---
B..|.E.|..P    BKW|AEI|DRP
A..|...|E..    ADP|WRB|EIK
ER.|P.K|B..    ERI|PDK|BWA

|. 3 ./. .|    |2 3 1/4 5|
|    /    |    |    /    |
|5 ./.\. .|    |5 4/2\1 3|
|\ /   \  |    |\ /   \  |
|.\1 . .\.|    |4\1 5 3\2|
|  \   / \|    |  \   / \|
|. .\4/. .|    |3 5\4/2 1|
|    /    |    |    /    |
|. ./. 5 .|    |1 2/3 5 4|

6 . . ./. 3     6 1 5 2/4 3
    ,-´            ,-´    
. ./. 5 . .     4 3/2 5 1 6
-----------     -----------
. 4 . ./. 5     3 4 6 1/2 5
    ,-´            ,-´    
5 ./. 4 6 .     5 2/3 4 6 1
-----------     -----------
. . . 3/. .     1 6 4 3/5 2
    ,-´            ,-´    
. ./1 . . .     2 5/1 6 3 4