PhD student, Inria MOCQUA
0 moves
Rows must have equal lengths. The circuit must implement the identity. Custom circuits use the same rules.
Reduce every wire to empty slots: this is the identity circuit. Read the circuit from left to right. Use as few moves as possible.
Select the cells shown in a rule, including empty slots, then choose that rule.
A yellow square (H) is a Hadamard gate, X flips a bit, and a green dot (Z) changes its phase. Linked green dots are a controlled Z; a red ⊕ endpoint turns the link into a controlled X (CNOT).
. H ↔ H .
. X ↔ X .
H H ↔ . .
X X ↔ . .
Z Z ↔ . .
ZU ZU / ZD ZD ↔ . . / . .
H Z H ↔ . X .
H X H ↔ . Z .
H ZU H ↔ . XU .
H ZD H ↔ . XD .
ZU ZU / XD XD ↔ . . / . .
XU XU / ZD ZD ↔ . . / . .
Z ZU . ↔ . ZU Z
Z ZD . ↔ . ZD Z
. ZU / ZU ZD / ZD . ↔ ZU . / ZD ZU / . ZD
X ZU / . ZD ↔ ZU X / ZD Z
. ZU / X ZD ↔ ZU Z / ZD X
ZU XU ZU / XD ZD XD ↔ XU ZU XU / ZD XD ZD
ZU ZU . / XD ZD . ↔ ZU ZU Z / ZD XD .
XU ZU . / ZD ZD . ↔ ZU XU . / ZD ZD Z
Click + between slots to add space. Right-click an empty slot to remove it; on touch screens, hold it. Shift-click + adds space on every wire. Tidy removes all unnecessary gaps. Space adjustments are free and can be undone.
Every rule works both ways. Introducing gates can help you simplify. Only rewrites count towards your score; moving gates through empty slots is free.
Levels introduce rules progressively using the missions in the original rules PDF. First derive an identity, then use its learned shortcut in later lessons. Random and daily puzzles use the complete learned rule set. Keyboard: R to reset, Backspace to undo, Escape to clear the selection.
Daily puzzles have a shortest solution of 10–14 moves. Rankings close at midnight in Paris; past puzzles remain playable as practice.
Practice completed.