Added example 6.15 of Gruntz thesis for aseries

[0sidharth]

References to other Issues or PRs

#7529

Brief description of what is fixed or changed

Added a test case from #7529 which was not added in master.

Other comments

Release Notes

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[0sidharth]

Enabling auto-merge as it is just the addition of a testcase.

[github-actions]

Benchmark results from GitHub Actions

Lower numbers are good, higher numbers are bad. A ratio less than 1
means a speed up and greater than 1 means a slowdown. Green lines
beginning with + are slowdowns (the PR is slower then master or
master is slower than the previous release). Red lines beginning
with - are speedups.

Significantly changed benchmark results (PR vs master)

Significantly changed benchmark results (master vs previous release)

Full benchmark results can be found as artifacts in GitHub Actions
(click on checks at the top of the PR).

[sympy-bot]

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#### References to other Issues or PRs
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#7529 

#### Brief description of what is fixed or changed
Added a test case from #7529 which was not added in master.

#### Other comments


#### Release Notes

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