Talk:Proper Subset of Finite Ordinal is Equivalent to Smaller Ordinal

I removed the "questionable" as it appears it may have been inspired by the typo $E$ for $x$ in the preamble to the definition of $f$ in case $(3)$ of the induction step. I have replaced that $E$ with an $x$. If there is still a problem with this, feel free to reply. --prime mover (talk) 12:02, 9 September 2012 (UTC)