Fix readme one last once

Author: shonfeder

README.org

@@ -3,13 +3,14 @@
 A (WIP) adaptation of the classic [[https://sites.google.com/site/prologsite/prolog-problems][99 Prolog Problems]] by [[https://sites.google.com/site/prologsite/author][Werner Hett]] to
 higher-order logic programming in [[http://www.lix.polytechnique.fr/~dale/lProlog/][λProlog]].
 
-Before undertaking the problems, you may wish to review this slight adaptation
-of Hett's wonderful guidance:
 
 * The spirit of the problems
+Before undertaking the problems, you may wish to review this slight adaptation
+of Hett's wonderful guidance (additions in =[]=):
 
+#+begin_quote
 The purpose of this problem collection is to give you the opportunity to
-practice your skills in higher-order logic programming. Your goal should be to
+practice your skills in [higher-order] logic programming. Your goal should be to
 find the most elegant solution of the given problems. Efficiency is important,
 but logical clarity is even more crucial. Some of the (easy) problems can be
 trivially solved using built-in predicates. However, in these cases, you learn
@@ -18,22 +19,24 @@ more if you try to find your own solution.
 Every predicate that you define should begin with a comment that describes it in
 a declarative statement.  Do not describe procedurally, what the predicate does,
 but write down a logical statement which includes the arguments of the
-predicate, and then describe the flow of data through the unification of terms.
+predicate, [and then describe the flow of data through the unification of terms].
+
+[Construct types to formalize the possible data for the predicates and
+functions, then specify the types and modes for their arguments.]
+#+end_quote
 
-Construct types to formalize the possible data for the predicates and
-functions, then specify the types and modes for their arguments.
 
 * The problems
 
-#+begin_src
+#+begin_quote
 The problems have different levels of difficulty. Those marked with a single
 asterisk (*) are easy. If you have successfully solved the preceeding problems
 you should be able to solve them within a few (say 15) minutes. Problems marked
 with two asterisks (**) are of intermediate difficulty. If you are a skilled
 Prolog programmer it shouldn't take you more than 30-90 minutes to solve them.
 Problems marked with three asterisks (***) are more difficult. You may need more
 time (i.e. a few hours or more) to find a good solution.
-#+end_src
+#+end_quote
 
 - [[file:problems/lists.org][Lists]]