39. Perpetual block is a draw. (See examples in Diagrams 99 and 100)

Diagram 99: Red (in Capital) moves first

C21 c98
C12 c89
C21 c98
C12 c89
C21 ....

Explanation:
The Black Cannon is "perpetually threatening to checkmate" and the Red Cannon is "perpetually blocking". Neither side violates the rule and the game can be a draw.


Diagram 100: Red (in Capital) moves first

R24 c86
R41 c69
R18 c12
R83 c97
R34 c76
....

Explanation:
Neither side violates the rule. It is a draw.