Glossary
The words used throughout the handbook, with their Vietnamese names alongside.
The board
- CellÔ
- One of the 81 squares on the board. Named by row and column: r3c5 is the cell in row 3, column 5.
- RowHàng
- Nine cells across, numbered 1–9 from top to bottom.
- ColumnCột
- Nine cells down, numbered 1–9 from left to right.
- BoxKhối
- A 3×3 area with a thick border, numbered 1–9 in reading order: box 1 top left, box 9 bottom right. Also called a block.
- UnitĐơn vị
- A row, column or box. Each unit must contain the digits 1–9 exactly once. The board has 27 units. Also called a house.
- Band and stackBăng ngang, băng dọc
- Three boxes side by side: a band runs across, a stack runs down. Scanning by band or stack speeds up finding hidden singles.
- GivenSố cho sẵn
- A digit printed in the puzzle. On the illustration boards, givens are bold ink; placed digits are handwritten in blue.
- Sees (peer)Nhìn thấy nhau
- Two cells see each other when they share a row, column or box. Each cell sees exactly 20 others, and two cells that see each other can never hold the same digit.
Notes
- CandidateỨng viên
- A digit that can still go in an empty cell: not yet in the cell's row, column or box, and not eliminated by reasoning.
- Pencil marksGhi chú bút chì
- Writing a cell's candidates in small digits. The usual layout puts digit d in position d of a 3×3 grid inside the cell, like a phone keypad.
- Bivalue cellÔ hai ứng viên
- A cell with exactly two candidates left. The raw material of naked pairs, XY-Wings, W-Wings and XY-Chains.
- EliminationLoại trừ
- Removing a candidate from a cell because it has been proven not to be the answer.
- PlacementĐiền số
- Writing the answer in a cell after proving it can only take that digit.
Reasoning
- SingleSingle
- The family of direct placements: full house, hidden single and naked single.
- Locked candidatesKhoá ứng viên
- When every place for a digit in one unit lies in its intersection with another unit. Includes pointing and claiming.
- Strong linkLiên kết mạnh
- Two candidates of which at least one must be true. For example: a unit with only two places for d, or a cell with only two candidates. "If not this, then that."
- Weak linkLiên kết yếu
- Two candidates that cannot both be true. For example: the same digit d in two cells that see each other. "If this, then not that."
- Conjugate pairCặp liên hợp
- The only two places for a digit in a unit. The most common kind of strong link.
- FishMẫu hình cá
- The family of techniques based on N rows and N columns for one digit: X-Wing (2), Swordfish (3), Jellyfish (4).
- WingWing
- A pattern with a pivot cell and pincers: XY-Wing, XYZ-Wing, W-Wing. It always concludes that one of a few cells certainly holds z.
- ChainChuỗi
- A sequence of candidates joined by alternating strong and weak links. Its ends tell you that at least one end is true.
- Deadly patternMẫu hình chết
- A group of cells whose digits could be swapped while the grid stays valid, giving the puzzle several solutions. Uniqueness techniques (Unique Rectangle, BUG) avoid it.
- Forcing chainChuỗi ép
- Try every option of a cell or unit in turn; if every branch leads to the same conclusion, that conclusion is true.