$command"; $gc = new GAPConnection('localhost', 1031); $ret = $gc->execute($command); $md = $gc->mode; $gc->close(); if ($md != 'i') { $ok = false; $msg .= '
'; } else { $msg .= '
Result: '; } $msg .= nl2br(htmlentities($ret)); } } ?>

The Vogel Algorithm

In Representation of links by braids, a new algorithm (Math. Helvetici 65 (1990), 104-113), Vogel describes an algorithm to manipulate a link diagram in such a way that an equivalent braid word may be read from it (Paper via SpringerLink). Andrew Bartholomew describes the algorithm in great detail in one of his papers as well.
We have implemented the algorithm in GAP, and it can be tested from this very website. In case of problems, please contact Dan Roozemond. One word of warning: For the moment, the algorithm only works for knots, i.e. links with only one component.
Enter a Gauss code and crossing signs below:
Gauss code: (e.g. )
Signs: (e.g. )