26. When a Cannon keeps attacking a Rook, disregard whether the Rook is protected or not, even if the Rook doesn't move and both sides only move the cannon mount, it is a perpetual chase. (See examples in Diagram 61 and 62)

Diagram 61: Red (in Capital) moves first

C2-7 n9+7
M5+3 n7+5
M3+5 n5-7
M5-3 n7-6
M3+5 ....
.

.


Diagram 62: Red (in Capital) moves first

C1-1 c8-1
G5-6 c8+1
G6+5 c8-1
G5-6 c8+1
G6+5 ....

Explanation:
In Diagrams 61 and 62, the Red Cannon moves the Guard or Minister to perpetually chase the Black Rook. Red has to change the move.