constitute a class of energy-preserving methods for the numerical
solution of canonical Hamiltonian systems, i.e., problems in the form:
J is a constant
skew-symmetric matrix, and H(y) is the Hamiltonian
methods are able to preserve, in the numerical solution, the value of
the Hamiltonian function, as it happens for the continuous one.
Hereafter, are the main facts about HBVMs: