fact: Definition Birkhoff_check1 cp := [&& cubic_prog cp, (cpcard cp).+1 < 6 * m + 4 * h & cprsize cp == h.+1].
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph) fourcolor(hypermap jordan geometry color chromogram) fourcolor(coloring patch snip sew revsnip kempe) fourcolor(ctree initctree gtree initgtree ctreerestrict) fourcolor(gtreerestrict cfmap cfcolor kempetree)