Error, unsupported type of index, n
The add command in Maple is used for adding an explicit sequence of values (in particular for list, Array, Matrix, or Vector), whereas the sum command is intended for symbolic summation. You will get this error message when the sum command is used to compute summation of aforementioned data structures instead of the add command.)
Summation of elements of a Vector:
Summation of elements of an Array:
Solution: Use add instead of sum.
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