set f = SpStSeq X;
(SpStSeq X) /. 2 = N-max (L~ (SpStSeq X)) by SPRECT_1:84;
then ( (SpStSeq X) /. 1 = N-min (L~ (SpStSeq X)) & (SpStSeq X) /. 2 in N-most (L~ (SpStSeq X)) ) by PSCOMP_1:42, SPRECT_1:83;
hence SpStSeq X is clockwise_oriented by Th30; :: thesis: verum