Formatting decision problems in LaTeX Is there a standard macro package, or just standard set of macros, for
  formatting decision problems in LaTeX?


A decision problem is presented via the data "problem name", "instance", and "question", with the latter always having a yes or no answer.  For example FACTOR has, as an instance, a pair of positive integers (n,p) and has, as its question, "Does n have a factor less that q and greater than one?".  Here is an attempt to format FACTOR in HTML.

FACTOR
Instance: $(n,q) \in \mathbb N \times \mathbb N$ 
Question: Does $n$ have a factor bigger than one and less than $q$?

In the interest of not reinventing the wheel, I asked google, and found some homegrown macros, each with their own spacing, choice of fonts, and layout.  Has anyone implemented a standard?  Say, a standard journal in complexity theory? 

For quite old examples of formatting choices see Karp's classic paper Reducibility among combinatorial problems, starting on page 89 (using the page numbers in the book, not in the pdf file).  The book Computers and intractability by Garey and Johnson also gives many decision problems - see page 25 of the linked text.  I've seen more recent texts where the problem name is in small caps, and the boiler-plate on the instance and question lines is in italics. 

For a more recent example, I found a macro written for use by students in a cs class - see lines 95 to 116.  

Finally - I tried asking over at the TeX Stack Exchange site, but didn't get any answers.  I've deleted the question there, and moved it over here.
For some obscure reason everyone is answering in comments, so let me comment in an answer. 

While I am not aware of any standard macros for this, I'm partial to the G&amp;J format (which is basically the format you use in the question. Namely, 


  PROBLEM NAME  
  INSTANCE: description of instance
  QUESTION: description of problem