fact: Definition converse_part p1 := let (h45, q4) := conv_part4 p1 in let (u, q5) := conv_part5 h45 (drop_part 2 p1) in let (h23, q12) := conv_part12 (drop_part 3 p1) in let q3 := conv_part3 h23 (drop_part 5 p1) in (u, q12 (q3 (q4 q5))).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph) fourcolor(hypermap color geometry)