VKCURVE is a joint project of
VKCURVE is a computer algebra package which computes a presentation of the fundamental group of the complement in the complex plane of an algebraic curve, following Van Kampen's method. It is written in GAP3. If, when using this package, you find any bugs, misdesigns, problems etc... (or if you just make an interesting use of the package), please send Email to us (David Bessis or Jean Michel).
Here is brief example of the package in action:
gap> FundamentalGroup(x^2-y^3); #I there are 2 generators and 1 relator of total length 6 1: bab=aba gap> FundamentalGroup((x+y)*(x-y)*(x+2*y)); #I there are 3 generators and 2 relators of total length 12 1: cab=abc 2: bca=abc
For more information you look at the manual online. You can also try VKCURVE online, an (experimental) web interface where you can directly enter a curve and get a result.
gap> FundamentalGroup(x^2-E(4)*y^3); #I there are 2 generators and 1 relator of total length 6 1: bab=aba