Countdown criteria for combo count (buy combo example)
1.close of current bar lower than or equal to low 2bar earlier (this condition is same as sequential)
2.close of current bar lower than close of previous bar.
3.low of current bar lower than low of previous bar.
4.close of current bar lower than close of previous combo bar.
Condition 4 is not present for combo countdown bar 1 as that is the first combo bar (with no previous combo bar in that countdown)
Vivek