(F,R) = firstOrderDeformations(F0,R0,T1)
F0, R0, and T1 should all be matrices over some common ring. R0 should be the first syzygy matrix of F0 and T1 should have the same number rows as the product of the number of rows and columns of F0.
F is a list of length two with F_0=F0 and F_1 the first order perturbations corresponding to T1. R is a list of length two with R_0=R0 and R_1 such that F_0*R_1+F_1*R_0==0. If SanityCheck is set to true, as is the default, then the algorithm will check that this equation is satisfied, and terminate with an error if this is not the case.
The parameters used in the perturbations may be specified by the option DefParam.
For example, consider the cone over the rational normal curve of degree four, see [Pi74]:
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The object firstOrderDeformations is a method function with options.
The source of this document is in VersalDeformations.m2:951:0.