Convert an algebraic tangle expression to a geometric zig-zag.
Supports leaf tangles −1, 0, 1 and compositions via TangleSum/TangleProduct.
- Parameters:
expr – int in {-1, 0, 1} or a TangleExpr.
- Returns:
ZigZag – Polyline representation with compass endpoints.
- Return type:
ZigZag
