I came across several visual representation of the 1x5x9 pattern defined for block precedence computation in the ultimate pit limit problem. But I can't seem to understand fully how it is computed. I plan to code an algorithm for this pattern defined by Gilbert (1966). I already coded the 1x5 and 1x9 patterns suggested by Lerchs & Grossman.
From the different papers that I found online, I sometimes see different visual representation of this specific 1x5x9 pattern. The first one that misleads me comes from the A new heuristic non-linear approach for modeling the variable slope angles in open pit mine planning algorithms (Seyed-Omid Gilani and Javad Sattarvand) research paper.
And the second one, which is different from the previous one, but seems rather strange to me comes from the Computer-Aided Optimal Open Pit Design With Variable Slope Angles (Reza Khalokakaie) research paper.
From what I understand, this 1x5x9 precedence pattern is an alternated version of the 1x5 (for odd levels) and 1x9 (for even levels).
Which one seems to be the perfectly defined one ?