F1 should be some first order perturbations of a matrix with R1 a lift of the corresponding relations, as in the output of firstOrderDeformations. M is a matrix representing the effect of these perturbations one order higher, and L gives a parameter-free version of the perturbations and lifted relations.
The object correctionMatrix is a method function.
The source of this document is in /build/reproducible-path/macaulay2-1.25.06+ds/M2/Macaulay2/packages/VersalDeformations.m2:994:0.