The procedure FormalSolution is an implementation in Maple 2015 of an algorithm to construct a basis of the space of formal exponential-logarithmic solutions for systems of differential equations with polynomial coefficients. The algorithm is based on the use of resolving sequences.
The details can be found in the preliminary version of the paper S.A.Abramov, M.Petkovšek, A.A.Ryabenko. Resolving sequences of operators for linear ordinary differential and difference systems.
The matrix form of a full-rank system:
An(x) diff(y(x),x$n) + … + A1(x) diff(y(x),x) + A0(x) y(x) = 0,
where
The normal form of a first order system:
y'(x) = A(x) y(x),
where
LDSformalsols.mpl - the Maple code of the procedure (implemented by A.A.Ryabenko).
Paper_Examples_FS.mw - the Maple session file with examples from the preliminary version of the paper.
Paper_Examples_FS.pdf - the pdf copy of that Maple session.