Question about x_h

*To*: mathgroup at yoda.physics.unc.edu*Subject*: Question about x_h*From*: tntg0367 at uxa.cso.uiuc.edu (Thao N Tran)*Date*: Fri, 18 Oct 1991 16:22:43 GMT

I would like to use "x_h" to do something like: newhead /: test[x_newhead] := new where I would define the head of the symbol somewhere else: Head[y] ^= newhead But this doesn't work. When I evaluate "test[y]", I get "test[y]" back. If I add a line: test[x_Symbol] := stillsymbol then "test[y]" gives "stillsymbol". So it seems like my "Head" assignment for the symbol "y" didn't go through. How can I make Mathematica understand what I mean? Thanks for your help. Thao Tran t-tran at uiuc.edu