Analysis techniques are calculated bar-by-bar from the oldes bar loaded to the chart to the most recent. On each bar onle current bar and all bars at the left of it are available. To access curent bar the following syntax is used: Bars. Previous bar is Bar, etc.
If on some step analysis technique requests too many bars back (for example, there are 10 bars back on current calculation step and analysis technique requests 11 bar back) calculation on current step is immidately stopped and application passes to the next step.