The returned list of loops contains each loop in CM in breadth-first search order). Each element in a loop is represented by its variable number, and the first element also terminates each loop.
References
Puccia, C. J. and Levins, R. (1986) Qualitative Modeling of Complex Systems: An Introduction to Loop Analysis and Time Averaging. Cambridge: Harvard University Press. <tools:::Rd_expr_doi("10.4159/harvard.9780674435070")>.