Paving incorrect for transcendental example from ACM TOMS paper on Filib++

[dpsanders]

For

C = Separator(vars, y - x - atan(log(sin(10x) / (x+1))) == 0)

Example from Fig. 10 of TOMS filib++ paper:

ACM Transactions on Mathematical Software, Vol. 32, No. 2, June 2006, Pages 299–324.

The inner region should be empty.

[dpsanders]

Perhaps the inverse function(s) for atan and/or log are incorrect.

[dpsanders]

Fixed in #212