Talk:Set of All Mappings of Cartesian Product

Any reason why R, S, T can not be sets, as opposed to small classes? From what I understand, small classes need to be used if it is required that proof techniques outside of ZF(C) be needed to prove things about them. Here I believe this is not the case, unless the language of mapping theory lacks that rigor.

Basically, this is a result in mapping theory, not class theory, am I right? --prime mover (talk) 08:25, 8 September 2012 (UTC)