fixed docstring format
2887: Fix bug with minpoly()

Make sure multinomials are expanded.
First, this is important for following the right code path.
Second, this ensures that mapping.values() is actually a list of polynomials (otherwise it could contain roots).
Merge pull request #2006 from pernici/cubic

Cubic
Merge pull request #2028 from katjasophie/2887_minpoly

2887: Fix bug with minpoly()
Add Katja Sophie Hotz to AUTHORS/aboutus. Welcome to SymPy!
replace cse 1*-1*foo detection with working version
fix wester test
apply_xsl real doctest instead of just usage example
806: Implement hyper.rewrite(Sum)

This adds the function _eval_rewrite_as_Sum to the class hyper.
Issue #3773: Error in acos(x).rewrite(atan)

Fixed acos(x).rewrite(atan) so that it accepts symbolic inputs.
Issue #3773: Added test case to check acos(x).rewrite(atan)

Added a test case to test_trigonometric to make sure
acos(x).rewrite(atan) produces the correct formula 2*atan(sqrt(1 -
x**2)/(1 + x))
Implement next_lexicographic and prev_lexicographic:wq
doctest_depends_on added, doctest corrected
Changed acos.rewrite(atan) to be more robust

The previous implementation of acos(x).rewrite(atan) produced outputs
which did not match with corresponding values from acos(x). A more
robust formula is used here to accommodate these errors.
Changed the test for acos(x).rewrite(atan)

Changed the test for acos(x).rewrite(atan) to accommodate the new
rewrite function
806: hyper.rewrite(Sum)

Change return value to Piecewise
Add tests
denest powers in powsimp so 4**s*2**(x-2*s) -> 2**x

Should this only be done if the base is a Number?
3341: allow factors of coeff to enter powers

* i order to make this work, multiplicity was made to handle Rationals.
Merge pull request #2031 from smichr/3341

3341 - allow powsimp to denest and process coefficients
added elementary arithmetic operations on algebraic numbers