-For convenience, the hi expression may be omitted; the notation
-a[lo :] is shorthand for a[lo : len(a)].
-For arrays or strings, the indexes
-lo and hi must satisfy
-0 <= lo <= hi <= length;
-for slices, the upper bound is the capacity rather than the length.
+For convenience, any of the index expressions may be omitted. A missing low
+index defaults to zero; a missing high index defaults to the length of the
+array, slice, or string.
+
+For arrays or strings, the indexes low and high must
+satisfy 0 <= low <= high <= length; for
+slices, the upper bound is the capacity rather than the length.