thus
not [.r1,r2,r19,r29.] is empty
; [.r1,r2,r19,r29.] is compact
A1:
(LSeg (|[r2,r29]|,|[r2,r19]|)) \/ (LSeg (|[r2,r19]|,|[r1,r19]|)) is compact
by COMPTS_1:10;
(LSeg (|[r1,r19]|,|[r1,r29]|)) \/ (LSeg (|[r1,r29]|,|[r2,r29]|)) is compact
by COMPTS_1:10;
hence
[.r1,r2,r19,r29.] is compact
by A1, COMPTS_1:10; verum