in[-1] <= 0 and in > 0

in[-1] >= 0 and in < 0

in[-1] <= 0 and in > 0

in[-1] >= 0 and in < 0

COUNTER[-1] + 1 WHEN (CNT_UP) COUNTER[-1] - 1 WHEN (CNT_DOWN) COUNTER[-1] OTHERWISE

tr1 OR tr2 OR tr3 OR tr4

tr1 OR tr2 OR tr3 OR tr4