Safe Navigation Operator “?.” for D2 ?

[Jesse Phillips]

On Sunday, 2 March 2014 at 01:28:32 UTC, deadalnix wrote:
> So, to make refactoring easier, you refactor. I knew the 
> functional crowd liked recursence, but I just learnt that tail 
> recusrion can also be used to crate circular logic.

I can't find what I'm thinking of, but Conditional Proof seems to 
be close:

http://en.wikipedia.org/wiki/Conditional_proof

This was used in my philosophy class. You start with an 
assertion, then list off things which are true because of it 
until you come back and the only logic conclusion is that the 
assertion was true.