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bbfuncm  Get functions for computing matrix-matrix products
   [f,fH,arg]=bbfuncm(BB) returns functions handles for computing
   the matrix-matrix products A*X and A'*X, where A corresponds to
   the black-box matrix BB.

   To evaluate a product use feval:
     Y=feval(f,X,arg{:})   computes Y=A*X
     X=feval(fH,Y,arg{:})  computes X=A'*Y

   Use bbfunc if you only need to evaluate matrix-vector products.
   Although the functions returned by bbfuncm also handles this case,
   it may be less efficient.

   See also , bbfunc, bbsimplify, bbinline.