superscript and subscript the same character in an expression

Question

In a plot I would like a title which should have:

the string \"my title is\" followed by the caharecter alpha raised by \' (i.e. alpha prime) with alph

Answer 1

Either of the following would do the trick:

alpha[G]^"'"
{alpha^{"'"}}[G]

They are typeset slightly differently, so pick whichever you prefer.

Answer 2

Changing the syntax to the following works:

expression(paste("my title is ",alpha[G]^{"'"},")")))