doctest that pynac series bug has been fixed

[DaveWitteMorris]

Pynac issue 207 says that exp(log(1+x)*(1/x)).series(x) raises a ValueError: power::eval(): division by zero, but it has worked fine at least as far back as 9.1:

sage: exp(log(1+x)*(1/x)).series(x)                                                                                      
(e) + (-1/2*e)*x + (11/24*e)*x^2 + (-7/16*e)*x^3 + (2447/5760*e)*x^4 + (-959/2304*e)*x^5 + (238043/580608*e)*x^6 + (-67223/165888*e)*x^7 + (559440199/1393459200*e)*x^8 + (-123377159/309657600*e)*x^9 + (29128857391/73574645760*e)*x^10 + (-5267725147/13377208320*e)*x^11 + (9447595434410813/24103053950976000*e)*x^12 + (-1447646915836493/3708162146304000*e)*x^13 + (225037938358318573/578473294823424000*e)*x^14 + (-29911565062525361/77129772643123200*e)*x^15 + (3651003047854884043877/9440684171518279680000*e)*x^16 + (-38950782815463986767/100969884187361280000*e)*x^17 + (104388909491649724435759747/271211974879377138647040000*e)*x^18 + (-843527474424845338522843/2196048379590098288640000*e)*x^19 + Order(x^20)

This ticket adds a doctest to ensure that the problem doesn't return.

Component: symbolics

Keywords: pynac, series

Author: Dave Morris

Branch/Commit: 87e8818

Reviewer: Frédéric Chapoton

Issue created by migration from https://trac.sagemath.org/ticket/32115

[DaveWitteMorris]

Branch: public/32115

[DaveWitteMorris]

Commit: 87e8818

[DaveWitteMorris]

New commits:

87e8818

trac 32115 doctest pynac series bug

[fchapoton]

comment:4

ok

[fchapoton]

Reviewer: Frédéric Chapoton

[DaveWitteMorris]

comment:5

Thanks for the review!

[vbraun]

Changed branch from public/32115 to 87e8818