Talk:Rice–Shapiro theorem

Assessment

I'm the page author and I've assessed it as importance=Low (it's a relatively obscure topic, even if it is a relatively important theorem in computability theory. --Blaisorblade (talk) 20:19, 16 July 2008 (UTC)

Stewart Shapiro

There are various Shapiro, and I just guessed it was Stewart Shapiro the one involved with this theorem; there is {{fact}} (i.e. ) about this in the page, but I wanted to make the doubt clear. --Blaisorblade (talk) 20:19, 16 July 2008 (UTC)

Duplicate

As far as I could understand, this page explains the Rice's Theorem, which (the other) page is more detailed. Hence, I think this page could be deleted and redirect to Rice's Theorem one. --Guiraldelli (talk) 15:13, 8 September 2015 (UTC)

Saved paragraph from article

I moved the following paragraph from the article here for discussion as it makes no sense: (a) the set $\{\theta :...\}$ is a set of functions and has no notion of recursively enumerability and (b) $n\in A$ where $n$ is an integer but $A$ denotes a set of functions. Martin Ziegler (talk) 00:11, 3 March 2017 (UTC)

In general, one can obtain the following statement: The set $\{n:\varphi _{n}\in A\}$ is recursively enumerable iff the following two conditions hold:

(a) $\{\theta :\theta =\varphi _{n}\forall n\in A\}$ is recursively enumerable;

(b) $n\in A$ iff $\exists$ a finite function $\theta$ such that $\varphi _{n}$ extends $\theta \wedge c(\theta )\in A$ where $c(\theta )$ is the canonical index of $\theta$.