Python code of the solution of the Robotic Arm Problem
(see D. Estévez Schwarz, R. Lamour, R. März Singularities of the
Robotic Arm DAE, DAE-Forum 2019)
Solution of DAE (see
Campbell 88, Campbell, Griepentrog 95) (DAE differs by one sign from
the original DeLuca, Isidori 85)
Solution of DAE (see
Campbell, Kunkel 2019) (Consistent with DeLuca, Isidori 85 for
parameters which lead to the Ca88-DAE)