Junk

> tau=tau( Twicubic(t), t );

> kappa=kappa( Twicubic(t), t );

> b=Binormal( Twicubic(t), t );

> n=UnitNormal( Twicubic(t), t );

> T=Tangent( Twicubic(t), t );

> foo:=linalg[crossprod]( Tangent(Twicubic(t),t),
UnitNormal(Twicubic(t),t) ):

> foo:=map( factor, foo );

> evalm( foo-Binormal( Twicubic(t), t ) );

> curveplot3D( Helix(Lemniscate(1,t),0.1,t), t=0..10,
shading=none, axes=box );

> tubecurveplot( Helix( Lemniscate(1,t), 0.1, t),
0.10, t=0..10, theta=0..2*Pi, axes=box,
scaling=unconstrained, grid=[100,10] );

> tau = simplify( tau( Helix( Lemniscate(a,t), c, t), t ), trig );