From: Henriette Elvang elvang [snail] umich.edu Aug 31 2012 To: Michael Stone Error in Appendix B =================== You are correct that our Young-projectors are not in general orthogonal, but only half-orthogonal. Stembridge refers back to Young for the statement that the tableaux A= 123 B= 135 45 24 are only half-orthogonal. It is indeed not hard to demonstrate that with our construction $P_B P_A = 0$ while $P_A P_B \ne 0$. So our construction yields projectors that are half-orthogonal and not fully orthogonal. The short argument given in appendix B is therefore too good to be true; we will revise it and correct the statement about orthogonality. The property we actually use is the orthogonality between projectors arising from distinct Young diagrams; we will clarify this when revising the text. Thank you for pointing this error out to us.