| I implemented a limited number of human-style patterns, which are then used as a pruning technique for the depth-first search performed by the guessing, so it won't be able to solve high-level puzzles without it, but it should solve all of them when it's enabled.
I implemented the following patterns as listed on this page:
- Singles
- Hidden Singles
- Locked Candidates 1 & 2
- Hidden Pairs
It can also load and solve the puzzles in the Advanced Puzzle Pack for the program referred to on that page (I tried most of them).
Here's a nice test case, which is said to require guessing:
...|..5|8.3
..7|..3|15.
...|.6.|..7
-----------
6..|38.|.7.
9..|...|..8
.3.|.79|..6
-----------
5..|.3.|...
.89|6..|2..
3.4|2..|...
(That's #3 from this Illogical Sudoku page. #14 has no solution according to my solver.) | 
