How can we define a function that works like f[x_]=ComputeSomething[x] and treats x as a variable that does not have a value? ...
v = Subscript[v, 0]*Sin[(Pi*S)/Subscript[S, 0]]; a = dv/ds v; a = D[v, s] returns ...
Consider the case where a symbol has multiple definitions attached to it, a /: Subscript[a,2] := 1 a[b_] := 2 a[b_, c_] := 3 How does one clear (/unset/remove) ...
When reading through the documentation, you often encounter the phrases DownValues, UpValues, ...
In a previous question on collecting terms for a multivariable polynomial, I answered with a solution that required a unused symbol to be used for a temporary substitution and back substitution. It ...