• Malisani regularization: see code here. The idea is to regularize the problem with the techniques from the article, not to solve it with the bvp algorithm. Solve with direct and indirect methods the examples from the article. Get inspiration from BVP-DAE.
• Log barrier and space (look for Epenoy ref). Reproduce page 44 Thèse Cots.

Future: we can have a function regularize on the abstract code.

@jbcaillau @joseph-gergaud Do you know the Epenoy ref about log barrier?