User talk:Dfeuer/Progressing Function Lemma

Smullyan and Fitting don't specify a domain or codomain for either the relation $R$ or the mapping $g$. The maximally general specification of these is fussy and probably not useful. I'm therefore rather tempted to limit $R$ to the domain of $g$, which appears likely to be the intention and is almost certainly sufficient for all applications in the text. --Dfeuer (talk) 03:21, 25 March 2013 (UTC)