# Clear the value of a subscripted variable?

Posted 2 months ago
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 I defined K_b: In[34]:= Subscript[K, b] = x y Out[34]= x y In[35]:= Subscript[K, b] Out[35]= x y  but then decided to clear the value (so I can later change the assignment to an equation ==). In[36]:= Clear[Subscript[K, b]] During evaluation of In[36]:= Clear::ssym: Subscript[K, b] is not a symbol or a string.  Why did this fail? ClearAll didn't work either.
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Posted 2 months ago
 Use: Subscript[k, b] =. I would stay away from subscripted symbols, because it may cause problems when substituting things as it is not seen as a single symbol: Subscript[k, b] /. k -> 3 gives 3_b 
Posted 2 months ago
 There is a general advice against the use of subscripts - as Sander did, because:I you make an assignment like this Subscript[k, b] = 1; a = 2; then with "normal" symbols OwnValues are created - but not in the case of Subscript:Instead the assignment to Subscript went (as kind of a function definition!) into DownValues:The only meaningful use of Subscript is (typically at the very end of a calculation) for displaying reasons.Does that help? Regards -- Henrik
Posted 2 months ago
 I've said it before: you should think of Subscript as a typographical construct.
Posted 2 months ago
 OK, thanks for the comments! -Jon
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