Here is what I believe to be a minimal set of fourteen m-wing and four m-ring exemplars. It is minimal in the sense that any valid m-wing (or m-ring) will match only one of the exemplars in this set. The lone exeption is shown in the Extensions section. For additional extensions, see StrmCkr's Addendum -- Useful Extensions to the Minimal Set{not restored} This thread was inspired by 999_Spring's and StrmCkr's postings {not restored} Thanks to both for the kickoff.
What I'm calling m-wing is generally known as "generalized" m-wing elsewhere. The original m-wing introduced by keith here is defined with five strong inferences, rather than the minimum three strong inferences required, as for an xy-wing and a w-wing. As the two extra strong inferences produce no extra eliminations AFAIK, it seems fair to say the original m-wing is "over-specified." Hence, the adjective "generalized" is dropped.
It is neither my expectation nor my intent that solvers use the "Type" numbers below. They are included merely to facilitate unambiguous discussion in this thread.
A general note about the exemplars: All cells required to be void (empty) of candidates 'a' and 'b' are not explicitly marked with '/'. However, there are only two grouped conjugate links and the unit (row, column, box) containing each should be clear. If not, I'm willing to consider changing the presentation.
Type 1A: Type 1B:
. . . | . . . | . . . . . . | . / . | . . .
. ab . | . . . | . -b . . ab . | . a . | . -b .
. . . | . . . | . . . . . . | . / . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . . . | . . . . . . | . / . | . . .
/ a / | / ab+ / | / b / / / / | / ab+ / | / b /
. . . | . . . | . . . . . . | . / . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . . . | . . . . . . | . / . | . . .
. . . | . . . | . . . . . . | . / . | . . .
. . . | . . . | . . . . . . | . / . | . . .
1A: r2c8 -b- r2c2 -a- r5c2 =a= r5c5 =b= r5c8 -b- r2c8 --> r2c8<>b
1B: r2c8 -b- r2c2 -a- r2c5 =a= r5c5 =b= r5c8 -b- r2c8 --> r2c8<>b
Type 2A: Type 2B:
. . . | . . . | . . . . . . | . / . | . . .
. ab . | . . -b | . . . . ab . | . a -b | . . .
. . . | . . . | . . . . . . | . / . | . . .
----------+----------+--------- ----------+----------+---------
. . . | / / b | . . . . . . | / / b | . . .
/ a / | / ab+ b | / / / . . . | / ab+ b | . . .
. . . | / / b | . . . . . . | / / b | . . .
----------+----------+--------- ----------+----------+---------
. . . | . . . | . . . . . . | . / . | . . .
. . . | . . . | . . . . . . | . / . | . . .
. . . | . . . | . . . . . . | . / . | . . .
2A: r2c6 -b- r2c2 -a- r5c2 =a= r5c5 =b= r456c6 -b- r2c6 --> r2c6<>b
2B: r2c6 -b- r2c2 -a- r2c5 =a= r5c5 =b= r456c6 -b- r2c6 --> r2c6<>b
Type 3A: Type 3B:
. . . | . b . | . . . . . . | . b . | . . .
. ab . |-b b -b | . . . . ab . |-b ab -b | . . .
. . . | . b . | . . . . . . | . b . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
/ a / | / ab+ / | / / / . . . | . ab+ . | . . .
. . . | . / . | . . . . . . | . / . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
3A: r2c46 -b- r2c2 -a- r5c2 =a= r5c5 =b= r123c5 -b- r2c46 --> r2c46<>b
3B: r2c46 -b- r2c2 -a- r2c5 =a= r5c5 =b= r123c5 -b- r2c46 --> r2c46<>b
Type 4A: Type 4B:
. . . | . / . | . . . . . . | . / . | . . .
. ab . |-b / -b | . . . . ab . |-b a -b | . . .
-b -b -b | . b . | . . . -b -b -b | . b . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
/ a / | / ab+ / | / / / . . . | . ab+ . | . . .
. . . | . / . | . . . . . . | . / . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
4A: r2c46 -b- r2c2 -a- r5c2 =a= r5c5 =b= r3c5 -b- r2c46 --> r2c46<>b,r3c123<>b
4B: r2c46 -b- r2c2 -a- r2c5 =a= r5c5 =b= r3c5 -b- r2c46 --> r2c46<>b,r3c123<>b
Type 5A: Type 5B:
. . . | . / . | . . . . . . | / / / | . . .
. ab . | . / . | . . . . ab . | a a a | . . .
a a a | / ab+ / | / / / . . . | / ab+ / | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
. -b . | . b . | . . . . -b . | . b . | . . .
. . . | . / . | . . . . . . | . / . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
5A: r5c2 -b- r2c2 -a- r3c123 =a= r3c5 =b= r5c5 -b- r5c2 --> r5c2<>b
5B: r5c2 -b- r2c2 -a- r2c456 =a= r3c5 =b= r5c5 -b- r5c2 --> r5c2<>b
Type 6A: Type 6B:
-b -b -b | b b b | . . . -b -b -b | b b b | . . .
. ab . | / / / | . . . . ab . | a a a | . . .
a a a | / ab+ / | / / / . . . | / ab+ / | . . .
----------+----------+--------- ----------+----------+---------
. . . | . . . | . . . . . . | . . . | . . .
6A: r1c123 -b- r2c2 -a- r3c123 =a= r3c5 =b= r1c456 -b- r1c123 --> r1c123<>b
6B: r1c123 -b- r2c2 -a- r2c456 =a= r3c5 =b= r1c456 -b- r1c123 --> r1c123<>b
Type 7A: Type 7B:
. . . | . . . | . . . . . . | / / / | . . .
. ab . | . . . |-b -b -b . ab . | a a a |-b -b -b
a a a | / ab+ / | b b b / / / | / ab+ / | b b b
----------+----------+--------- ----------+----------+---------
. . . | . . . | . . . . . . | . . . | . . .
7A: r2c789 -b- r2c2 -a- r3c123 =a= r3c5 =b= r3c789 -b- r2c789 --> r2c789<>b
7B: r2c789 -b- r2c2 -a- r2c456 =a= r3c5 =b= r3c789 -b- r2c789 --> r2c789<>b
Type A:
. -a . | . / . | . . .
-b ab -b |-b b -b |-b -b -b
. -a . | . / . | . . .
------------+----------+---------
. -a . | . / . | . . .
/ a / | / ab+ / | / / /
. -a . | . / . | . . .
------------+----------+---------
. -a . | . / . | . . .
. -a . | . / . | . . .
. -a . | . / . | . . .
In addition, r5c5=ab
r2c2 -a- r5c2 =a= r5c5 =b= r2c5 -b- r2c2 - continuous loop
Type B:
-a -a -a | / / / | . . .
-ab ab -ab| b b b |-b -b -b
a a a | / ab+ / | / / /
----------+-----------+---------
. . . | . . . | . . .
In addition, r3c5=ab
r2c2 -a- r3c123 =a= r3c5 =b= r2c456 -b- r2c2 - continuous loop
Type: B1 -- added by strmckr {oct 19,2017},
-a -a -a | / / / | . . .
-ab ab -ab | b b b |-b -b -b
/ a / | / ab+ / | / / /
------------+----------+---------
. -a . | . . . | . . .
. -a . | . . . | . . .
. -a . | . . . | . . .
------------+----------+---------
. -a . | . . . | . . .
. -a . | . . . | . . .
. -a . | . . . | . . .
In addition, r3c5=ab
r2c2 -a- r3c2 =a= r3c5 =b= r2c456 -b- r2c2 - continuous loop
Type: AB
-a -a -a | . / . | . . .
-ab ab -ab | -b b -b |-b -b -b
/ a / | / ab+ / | / / /
------------+----------+---------
. -a . | . / . | . . .
. -a . | . / . | . . .
. -a . | . / . | . . .
------------+----------+---------
. -a . | . / . | . . .
. -a . | . / . | . . .
. -a . | . / . | . . .
In addition, r3c5=ab
r2c2 -a- r3c2 =a= r3c5 =b= r2c5 -b- r2c2 - continuous loop
Type C:
-ab -ab -ab | . . . | . . .
-ab ab -ab | . . . | . . .
ab* ab* ab* | / ab+ / | / / /
------------+----------+---------
. . . | . . . | . . .
In addition, r3c5=ab
r2c2 -a- r3c123 =a= r3c5 =b= r3c123 -b- r2c2 - continuous loop
Type D:
. . . | / / / | . . .
-ab ab -ab |ab* ab* ab*|-ab -ab -ab
. . . | / ab+ / | . . .
------------+-----------+-----------
. . . | . . . | . . .
In addition, r3c5=ab
r2c2 -a- r2c456 =a= r3c5 =b= r2c456 -b- r2c2 - continuous loop
Type 2C: (Simultaneously a Type 2A and a transposed Type 2B)
. . . | . . . | . . .
. ab . | . . -b | . . .
. . . | . . . | . . .
--------+---------+-------
. . . | / / / | . . .
/ a / | / ab+ / | / / /
. -b . | / / b | . . .
--------+---------+-------
. . . | . . . | . . .
2: r2c6 -b- r2c2 -a- r5c2 =a= r5c5 =b= r6c6 -b- r2c6 --> r2c6<>b,r6c2<>b
# m-wing1A:
9...5..3....1....8..6...4.2....7..2...42.68...9..3....8.3...2..7....9....4..8...6 # Ruud50k #17852
7.3..1..6.......3..9.6..2......7.8.1...3.2...5.8.9......1..4.2..7.......6..8..4.9 # Ruud50k #37876
..5..3.1...7.6....3.91.7..........25..8...9..74..........2.84.9....1.5...6.9..8.. # Ruud50k #39657
# m-wing1B:
......61......85..3..6...48...7.24.9..6...1..7.83.4...86...9..5..21......79...... # Ruud50k #19424
.....8.1...51..7.....92........6.....73...94....8..6.742...5....3..4.16...1....5. # Mike Barker
# m-wing2A:
..532.61...9.17.8.......4......8..5.9.......3.3..4......6.......1.45.3...83.627.. # Ruud50k #17199
9835...4....1.....2....3..8.....17..45.....92..62.....1..3....9.....4....4...5617 # Ruud50k #30439
# m-wing2B:
.....1..3....4..6..2.98..5....4.25....7...9....37.8....6..17.4..3..6....5..8..... # Ruud50k #20702
..2....35.1.....8....1.7.2.7....19......5......47....8.5.2.3....8.....4.92....8.. # Ruud50k #49585
# m-wing2C:
..6.5.......7...35....9..2..4.....875...8...127.....4..5..4....32...8.......1.9.. # Ruud50k #10270
...2......5.83.41.24...6..8..7..1...1.......6...4..3..3..1...87.91.62.3......4... # Ruud50k #41729
# m-wing3A:
..5.....4..36...1..1...26..8...1..5..7.....2..3..8...1..25...9..8...94..9.....7.. # Ruud50k #23559
# m-wing3B:
..4....1.7.15....8.8....9.....3.9...64.8.2.95...6.5.....8....6.3....45.9.2....1.. # Ruud50k #25209
.....1...6...98.1...54....34...7.........4..6..691..5..8...723..4......9..25..... # sudogen17 #136
# m-wing4A:
....9.1...6.3..74....4..2....4.5..1.6.......5.2..3.9....5..7....71..6.2...6.1.... # Ruud50k #21429
...67..242...........51.....4.....69..27.......8...31..5..3..4.4.....8.6...8.57.3 # sudogen4 #99874
....8..5.8.2.....3.3..6..42.46.1.............5.12.6...4........28.9..3.7........5 # sudogen4 #23891
# m-wing4B:
..4.1..5...1..53....73....2.8...9.2..95..7..3.......79...6.2...6....1.9.2.95...4. # Ruud50k #18611mrph
# m-wing5A:
.5...8..1..4.62.....8..1..2.9....6.5....3....8.2....9.5..6..1.....29.7..4..7...3. # Ruud50k #24894
.....254...94...2..4.81...6.5..7.9..2.......3..8.4..1.3...69.8..2...41...943..... # Ruud50k #34328
......6.9....7.5..6......1..7..412..9..2......4.9....8..3..4.....9.13.875.......3 # sudogen23 #949
9...8..6.87.4......52....1.2.9.7.........1..2..76.91.5.9..57.3..2...4.5....8..... # sudogen31 #2856
# m-wing5B:
..8.4.......9..45......5..7.2..19...97..8..41...47..8.3..6......85..3.......9.2.. # Ruud50k #19232
# m-wing6A:
.3.2...4...7.....8.2.64.....4.36....6...5...1....81.7.....17.8.9.....5...1...6.2. # Ruud50k #32681
# m-wing6B:
# m-wing7A:
...7.3...78.........3.18.6.............3.621..1.58...9.5....1.24........62..9.4.8 # Allan Barker
# m-wing7B:
.....8.9.1.....7.8..879..13.2......1.1..8..5.6......2.48..362..7.1.....4.3.4..... # Ruud50k #13610
.43...7......6....68..79...........8..1.8.3.....5..1.4.....1.6..5...2..39.7...8.. # Mike Barker
# m-ringA:
.4...5..9..8...3.......9.7.7..2...4.3..5.6..2.6...7..1.2.9.......7...5..4..8...3. # Ruud50k #27013
2....4.1......8.49..79...3.38.4....2....7....4....3.61.3...95..92.5......6.1....3 # Ruud50k #28880
# m-ringB:
..2397...18....2....9..8......26...8.6.....4.9...81......7..5....7....24...5198.. # Ruud50k #39874
# m-ringC:
6...5..9...7.....3.....847......4...7.2...5.1...9......593.....1.....6...8..1...7 # Ruud50k #29693
.....6.......385929.....7..5....4.8..6..8..3..7.6....9..2.....171346.......5..... # Ruud50k #22750
51.....2......1..8...6.73...4......7..9.6....6..4.....2..8..93.9.....5.4.8.....1. # sudogen17 #8686
# m-ringD:
.....21.....3...84....915...1...9..62.......35..8...9...394....48...7.....56..... # Ruud50k #6698
.......5..65.3.1...731....92...9.4.6.9..1..3..36.........2.19..........7...4.9..3 # sudogen1 #3959
# m-wing2A
...2.5.6.4......1...6.9..35...7..5.2.........3.9..6...52..8.1...8......3.6.5.4... # Ruud50k #16508
# m-wing6A:
.3......272...9.1...9.5....5....6.....3.8.6.....7....8....4.5...4.8...736......9. # Ruud50k #12277
9...5.6.3.......4..4..6...21.2..9.....3...7.....3..1.54...8..7..3.......6.7.1...9 # Ruud50k #18408
# m-wing6B:
8..7....4.5....6............3.97...8....43..5....2.9....6......2...6...7.71..83.2 # top95 #70
# m-wing7A:
..3...9...26.....1....94.6.1..9.....5..4.7..8.....8..5.1.72....6.....72...8...1.. # Ruud50k #2670
# m-ringA:
6.8...94......48161.......5...5....2....9.6...8...27..95..671..86......9.238...6.
# m-ringB:
....71.......6..1.6..2..3...6.9..12..5.....4..98..4.6...5..2..7.8..9.......41.... # Ruud50k #16911
# m-ringD:
....36.....15...2.6.3...1...4.7....8.3.....9.1....2.6...9...8.6.7...85.....34.... # Ruud50k #12595
daj95376 wrote: StrmCkr requested that I post the puzzles that ronk found for his exemplars.
Leren wrote:I've tested all of these and they work pretty much as described except for #20702 which would be better placed in the non-robust section.
Also both Type 2C puzzles only make one elimination and could just as well be described as type 2A's. Can anyone provide an example of a puzzle
with a Type 2C M Wing that makes 2 eliminations, or is this just a theoretical construct for which no real life example has been found?
Puzzle #8: m-wing2B: Ruud50k #20702
.....1..3....4..6..2.98..5....4.25....7...9....37.8....6..17.4..3..6....5..8.....
+-----------------------+
| . . . | . . 1 | . . 3 |
| . . . | . 4 . | . 6 . |
| . 2 . | 9 8 . | . 5 . |
|-------+-------+-------|
| . . . | 4 . 2 | 5 . . |
| . . 7 | . . . | 9 . . |
| . . 3 | 7 . 8 | . . . |
|-------+-------+-------|
| . 6 . | . 1 7 | . 4 . |
| . 3 . | . 6 . | . . . |
| 5 . . | 8 . . | . . . |
+-----------------------+
c1b4 Locked Candidate 1 <> 2 r78c1
c9b6 Locked Candidate 1 <> 4 r3c9
r7 b7 Locked Candidate 2 <> 9 r8c13,r9c23
Multiple Colors <> 7 r3c9 (part of SSTS)
c1b4 Locked Candidate 2 <> 1 r4c23,r6c2
c7b3 Locked Candidate 2 <> 7 r2c9
c2 Hidden Pair = 17 r29c2
+--------------------------------------------------------------+
| 489 489 5 | 6 7 1 | 248 289 3 |
| 3 17 189 | 2 4 5 | 78 6 89 |
| 467 2 46 | 9 8 3 | 47 5 1 |
|--------------------+--------------------+--------------------|
| 1689 89 689 | 4 39 2 | 5 1378 78 |
| 248 458 7 | 1 35 6 | 9 238 248 |
| 1249 459 3 | 7 59 8 | 6 12 24 |
|--------------------+--------------------+--------------------|
| 89 6 289 | 3 1 7 | 28 4 5 |
| 478 3 248 | 5 6 49 | 1 2789 2789 |
| 5 17 14 | 8 2 49 | 3 79 6 |
+--------------------------------------------------------------+
# 64 eliminations remain
M-Wing 2B (4=7)r3c7 - r3c1 = (7-4)r8c1 = (4)r89c3 => r3c3<>4
Solution:
495671283318245769726983451689432517247156938153798624962317845834569172571824396
Puzzle #315: from top1465
8.2.....4.9......7..5..139..8..17......5.2..1.....8.36..71.....4...7....32...5...
+-----------------------+
| 8 . 2 | . . . | . . 4 |
| . 9 . | . . . | . . 7 |
| . . 5 | . . 1 | 3 9 . |
|-------+-------+-------|
| . 8 . | . 1 7 | . . . |
| . . . | 5 . 2 | . . 1 |
| . . . | . . 8 | . 3 6 |
|-------+-------+-------|
| . . 7 | 1 . . | . . . |
| 4 . . | . 7 . | . . . |
| 3 2 . | . . 5 | . . . |
+-----------------------+
r6 b5 Locked Pair <> 49 r4c4,r5c5,r6c1237
r9 b9 Hidden Pair = 17 r9c78
r7 b9 Locked Candidate 1 <> 4 r7c56
r7 b7 Locked Candidate 1 <> 5 r7c789
Multiple Colors <> 3 r1c4
+-----------------------------------------------------------------------+
| 8 367 2 | 679 3569 369 | 156 156 4 |
| 1 9 r36 | 2368 2358-6 4 | 2568 2568 7 |
| 67 4 5 | 2678 268 1 | 3 9 28 |
|-----------------------+-----------------------+-----------------------|
| 2569 8 s3469 | t36 1 7 | 2459 245 259 |
| 679 367 439-6 | 5 u36 2 | 4789 478 1 |
| 257 57 1 | 49 49 8 | 257 3 6 |
|-----------------------+-----------------------+-----------------------|
| 569 56 7 | 1 23689 369 | 24689 2468 2389 |
| 4 1 689 | 23689 7 369 | 25689 2568 23589 |
| 3 2 689 | 4689 4689 5 | 17 17 89 |
+-----------------------------------------------------------------------+
# 117 eliminations remain
debug: ux_0_l = 000002004001 unit containing [ab]
debug: ux_0_r = 000002004001 unit containing [ab]
debug: ux_1_l = 000010004010 units containing [a/aaa]
debug: ux_1_r = 000010010020 unit containing [ab+]
debug: ux_2_l = 000010010020 unit containing [ab+]
debug: ux_2_r = 000020020020 units containing [b/bbb]
debug: ux_wrk = 000000000000 units containing all elims
debug: ux_xyz = 000000000000 units containing [b/bbb] & all elims
debug: ux_xyz = 000000000000 units containing [ab] & all elims
format: crb_x_x { "x" -->> count_bits( ux_2_l XOR ux_2_r ) == 4 }
M-Wing 2C (6=3)r2c3 - r4c3 = (3-6)r4c4 = (6)r5c5 => r2c5,r5c3<>6
*** also present ***
debug: ux_0_l = 000002004001 unit containing [ab]
debug: ux_0_r = 000002004001 unit containing [ab]
debug: ux_1_l = 000010004010 units containing [a/aaa]
debug: ux_1_r = 000010010020 unit containing [ab+]
debug: ux_2_l = 000010010020 unit containing [ab+]
debug: ux_2_r = 000010000010 units containing [b/bbb]
debug: ux_wrk = 000020004010 units containing all elims
debug: ux_xyz = 000000000010 units containing [b/bbb] & all elims
debug: ux_xyz = 000000004000 units containing [ab] & all elims
format: crR_b_c
M-Wing 3B (6=3)r2c3 - r4c3 = (3-6)r4c4 = (6)r4c13 => r5c3<>6
*** not solvable as non-Robust using ronk's constraints for his examples ***
Solution:
8.2.....419...4..7.45..139..8..17......5.2..1..1..8.36..71.....41..7....32...5...
*--------------------------------------------------------------*
| 8 7 2 | 9 3 6 | 15 15 4 |
| 1 9 3 | 28 5 4 | 268 268 7 |
| 6 4 5 | 7 b28 1 | 3 9 a28 |
|--------------------+--------------------+--------------------|
| 29 8 6 | 3 1 7 | 2459 245 259 |
| 79 3 4 | 5 6 2 | 789 78 1 |
| 27 5 1 | 4 9 8 | 27 3 6 |
|--------------------+--------------------+--------------------|
| 5 6 7 | 1 c28 39 | 2489 248 2389 |
| 4 1 89 |d28 7 39 | 25689 2568 359-28 |
| 3 2 89 | 6 4 5 | 17 17 89 |
*--------------------------------------------------------------*
M-Wing: (X=Y)a - (Y)b ... = (Y-X)c = (X)d strong link at weak inferences
gM-Wing: (X=Y)a - (Y)b ... = (Y-X)c = (X)d no constraint at weak inferences
=> elims for (X) in peers common to "a","d"
Leren wrote:M Wing Type 2C: (8=2) r3c9 - r3c5 = (2-8) r7c5 = r8c4 => - 8 r8c9, followed immediately by
M Wing Type 2C: (2=8) r3c9 - r3c5 = (8-2) r7c5 = r8c4 => - 2 r8c9
That's two M Wing Type 2C's that are identical except that the roles of a and b are reversed.
Could there be a case for an M Wing type 2D that may produce up to 4 eliminations, or is it just remote pairs by another name .... hmmmm
Leren wrote:A while ago you posted the following definitions:
- Code: Select all
M-Wing: (X=Y)a - (Y)b ... = (Y-X)c = (X)d strong link at weak inferences
gM-Wing: (X=Y)a - (Y)b ... = (Y-X)c = (X)d no constraint at weak inferences
=> elims for (X) in peers common to "a","d"
Is there a gM-Wing that isn't covered by M Wings Types 1-7 ?
ronk wrote:What I'm calling m-wing is generally known as "generalized" m-wing elsewhere. ... Hence, the adjective "generalized" is dropped.
Type: B1 -- added by strmckr {oct 19,2017}, noticed its exclusion based on phill example
-a -a -a | / / / | . . .
-ab ab -ab | b b b |-b -b -b
/ a / | / ab+ / | / / /
------------+----------+---------
. -a . | . . . | . . .
. -a . | . . . | . . .
. -a . | . . . | . . .
------------+----------+---------
. -a . | . . . | . . .
. -a . | . . . | . . .
. -a . | . . . | . . .
In addition, r3c5=ab
r2c2 -a- r3c2 =a= r3c5 =b= r2c456 -b- r2c2 - continuous loop
Type: AB -- added by strmckr {oct 19,2017}, patterned noted as a missing M-ring by Leren
example puzzle found by PJB
Type: AB
-a -a -a | . / . | . . .
-ab ab -ab | . b . |-b -b -b
/ a / | / ab+ / | / / /
------------+----------+---------
. -a . | . / . | . . .
. -a . | . / . | . . .
. -a . | . / . | . . .
------------+----------+---------
. -a . | . / . | . . .
. -a . | . / . | . . .
. -a . | . / . | . . .
In addition, r3c5=ab
r2c2 -a- r3c2 =a= r3c5 =b= r2c5 -b- r2c2 - continuous loop
# m-ringAB: .7..2..8.......1.2..36.....3....52...4..7..9..9...8..68..5.......9.....1.6..3.92. # ArkieTech # 18 Oct 2017
Type 8A: Type 8B:
-b -b -b | . +b . | . . . -b -b -b | / +b / | . . .
. ab . | . / . | . . . . ab . |+a +a/ +a | . . .
+a +a +a | / +ab / | / / / . . . | / +ab / | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
----------+----------+--------- ----------+----------+---------
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
. . . | . / . | . . . . . . | . / . | . . .
Leren wrote:It looks to me like the removals of b in Box 2 of both types are unnecessary, because there are only 2 b's in Column 5, both in Box 2, and they would have been removed by a claiming intersection on b in Box 2.
Leren