Fib (Mind Loft)

About Fib (Mind Loft)

Fib starts as a futoshiki: a 5x5 grid where each row and column holds the digits 1 to 5 once, a few digits are printed, and small signs between neighbouring squares say which of the two is larger. The twist is that exactly one of those signs is false.

That one change alters how you reason. In an ordinary grid a contradiction means you made a mistake somewhere; in Fib it might mean you have found the lie. So every chain of deductions carries a second question, and the sign you trusted first may be the one worth doubting. When your grid is complete, you tap the sign you are accusing and submit.

Each board is checked to allow exactly one grid and exactly one lying sign, so the answer can be proved without guessing. There are Notes, Undo and a hint, and errors are counted. A new grid arrives every day at midnight Eastern, and Sundays use a 6x6 grid.

How to play Fib (Mind Loft)

1. Open Fib and press Start.
2. Fill the grid so every row and column holds 1 to 5 once, using the signs between squares (the open end points at the larger number).
3. When the signs cannot all be true, work out which single sign is the lie.
4. Tap the sign you are accusing and press Submit.

Tips

• Look for chains of signs that would force impossible values, such as five squares in a strict increasing run with a printed digit in the wrong place.
• Solve the parts of the grid that do not depend on any sign first; the printed digits and Latin square rules alone settle some squares.
• If two signs conflict, test the grid with each one removed; only one choice leaves a valid solution.

Questions