function C = gradeinvolution(A)%gradeinvolution(A): returns the grade involution of a multivector.%%See also gable.% GABLE, Copyright (c) 1999, University of Amsterdam% Copying, use and development for non-commercial purposes permitted.%          All rights for commercial use reserved; for more information%          contact Leo Dorst (leo@wins.uva.nl).%%          This software is unsupported.     T=GA([A.m(1);-A.m(2);-A.m(3);-A.m(4);A.m(5);A.m(6);A.m(7);-A.m(8)]);     if GAautoscalar&isascalar(T)	C=T.m(1);     else	C=T;     end