The SubString(s, r) command returns a substring of string s specified by range r. A substring is a sequence of characters that occurs contiguously in the original string from which it is selected.

The range r must have integer endpoints. Range indexing for this function is similar to substring selection via the  notation. For more information about range indexing, see selection.

The main difference between Substring and the Maple built-in substring procedure is that, when presented with a symbol as the first argument, substring returns a symbol while SubString returns a string.