This webpage contains supplementary materials for the paper Tying Up Loose Strands: The Defining Equations of the Strand Symmetric Model by Colby Long and Seth Sullivant.
The file SSM_Supplement.m2 can be run in Macaulay2 to explicitly construct the chain of ideals described in Section 2.3. As outlined in that section, the existence of this chain constitutes sufficient proof of Lemma 2.6 that the ideal generated by cubics and quartics is prime. Additionally, the file contains the computations necessary to verify the claims made in Theorem 2.2 regarding the degree, dimension, and Hilbert Series of the vanishing ideal of the strand symmetric model on the claw tree. The entire file should execute in less than an hour on a standard laptop.