Would it be a good idea to change Python definition so that a[10, -1, -1] referred to the elements starting with position 10, going down to the beginning?
This would require disabling the "negative stop value means counting from the end of the array" magic whenever the step value is negative. The reason for this idea is that many people (me including) try to use extended slices with negative step values, only to realize that they are messed up. For example, if your stop value is reduced in a loop from a positive number to -1, the behavior breaks whenever it hits -1.
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