# Author: Erik Winfree
# Uses internal states:  for Competition 2.

X + 0 -> 0 + X (10)
X + 1 -> 0 + X1 (10)
X + 2 -> 1 + X2 (10)
X + 3 -> 2 + X3 (10)
X + 4 -> 3 + X4 (10)
X + 5 -> 4 + X5 (10)
X + 6 -> 5 + X6 (10)
X + 7 -> 6 + X7 (10)
X + 8 -> 7 + X8 (10)
X + 9 -> 8 + X9 (10)

XB + 0 -> 9 + XB (10)
XB + 1 -> 9 + XB (10)
XB + 2 -> 9 + XB (10)
XB + 3 -> 9 + XB (10)
XB + 4 -> 9 + XB (10)
XB + 5 -> 9 + XB (10)
XB + 6 -> 9 + XB (10)
XB + 7 -> 9 + XB (10)
XB + 8 -> 9 + XB (10)
XB + 9 -> 9 + XB (10)

X1 + 1 -> 0 + X1 (10)
X1 + 2 -> 1 + X2 (10)
X1 + 3 -> 2 + X3 (10)
X1 + 4 -> 3 + X4 (10)
X1 + 5 -> 4 + X5 (10)
X1 + 6 -> 5 + X6 (10)
X1 + 7 -> 6 + X7 (10)
X1 + 8 -> 7 + X8 (10)
X1 + 9 -> 8 + X9 (10)

X2 + 2 -> 1 + X2 (10)
X2 + 3 -> 2 + X3 (10)
X2 + 4 -> 3 + X4 (10)
X2 + 5 -> 4 + X5 (10)
X2 + 6 -> 5 + X6 (10)
X2 + 7 -> 6 + X7 (10)
X2 + 8 -> 7 + X8 (10)
X2 + 9 -> 8 + X9 (10)

X3 + 3 -> 2 + X3 (10)
X3 + 4 -> 3 + X4 (10)
X3 + 5 -> 4 + X5 (10)
X3 + 6 -> 5 + X6 (10)
X3 + 7 -> 6 + X7 (10)
X3 + 8 -> 7 + X8 (10)
X3 + 9 -> 8 + X9 (10)

X4 + 4 -> 3 + X4 (10)
X4 + 5 -> 4 + X5 (10)
X4 + 6 -> 5 + X6 (10)
X4 + 7 -> 6 + X7 (10)
X4 + 8 -> 7 + X8 (10)
X4 + 9 -> 8 + X9 (10)

X5 + 5 -> 4 + X5 (10)
X5 + 6 -> 5 + X6 (10)
X5 + 7 -> 6 + X7 (10)
X5 + 8 -> 7 + X8 (10)
X5 + 9 -> 8 + X9 (10)

X6 + 6 -> 5 + X6 (10)
X6 + 7 -> 6 + X7 (10)
X6 + 8 -> 7 + X8 (10)
X6 + 9 -> 8 + X9 (10)

X7 + 7 -> 6 + X7 (10)
X7 + 8 -> 7 + X8 (10)
X7 + 9 -> 8 + X9 (10)

X8 + 8 -> 7 + X8 (10)
X8 + 9 -> 8 + X9 (10)

X9 + 9 -> 8 + X9 (10)
X9 + 1 -> 0 + X (1)

# The plaXer in posession of the ball emits a stream of 9s.
# The other plaXers degrade the counts and strictlX climb or coast.
# (And occasionallX revert.)
