' is often used when we want to distinguish two variables. For example, if we already have a variable
t and we may want define another variable
t'. What I found weird is that, in *Mathematica` it is legitimate to define a variable with apostrophe but it just can't clear a variable which has an apostrophe in the usual way.
For example, if we write the following
3t' will correctly give
Clear[t'] will prompt an error says
Clear::ssym: t' is not a symbol or a string
Can anyone help?