the group and hopefully get to a point where you can read it again and
get more out of. (Rinse and repeat.)
-
-## General issues about variables and binding in programming languages ##
-
-* [[!wikipedia Variable (programming) desc="Variables"]]
-* [[!wikipedia Variable shadowing]]
-* [[!wikipedia Scope (programming) desc="Variable scope"]]
-* [[!wikipedia Free variables and bound variables]]
-* [[!wikipedia Name binding]]
-* [[!wikipedia Name resolution]]
-* [[!wikipedia Parameter (computer science) desc="Function parameters"]]
-
-## Functions as values, etc ##
+## Functions ##
* [[!wikipedia Higher-order function]]
* [[!wikipedia First-class function]]
-* [[!wikipedia Closure (computer science) desc="Closures"]]
* [[!wikipedia Currying]]
## Functional vs imperative programming ##
* [[!wikipedia Referential transparency (computer science)]]
* [[!wikipedia Imperative programming]]
+## General issues about variables and scope in programming languages ##
+
+* [[!wikipedia Variable (programming) desc="Variables"]]
+* [[!wikipedia Free variables and bound variables]]
+* [[!wikipedia Variable shadowing]]
+* [[!wikipedia Name binding]]
+* [[!wikipedia Name resolution]]
+* [[!wikipedia Parameter (computer science) desc="Function parameters"]]
+* [[!wikipedia Scope (programming) desc="Variable scope"]]
+* [[!wikipedia Closure (computer science) desc="Closures"]]
+
+##[[Learning Scheme]]##
+
+* [Try Scheme in your web browser](http://tryscheme.sourceforge.net/)
+
## Untyped lambda calculus and combinatory logic ##
* [[!wikipedia Lambda calculus]]
+* Our [[Lambda evaluator]]
* [Chris Barker's Lambda Tutorial](http://homepages.nyu.edu/~cb125/Lambda)
-* [Lambda Animator](http://thyer.name/lambda-animator/)<p>
+* [Lambda Animator](http://thyer.name/lambda-animator/)
+* [Penn lambda calculator](http://www.ling.upenn.edu/lambda/) Pedagogical software developed by Lucas Champollion, Josh Tauberer and Maribel Romero.<p>
+
<!-- Haskell Curry had ideas that he felt were validated upon reading a 1924 paper by M. Schönfinkel "Uber die Bausteine der mathematischen Logik" which used combinators in a similar way to his own ideas. Haskell then wrote "An analysis of logical substitution" which appeared in the American Journal of Mathematics in 1929. -->
* [[!wikipedia Moses Schönfinkel]]
* [[!wikipedia Haskell Curry]]
* [[!wikipedia Alonzo Church]]<p>
+* [[!wikipedia Church encoding]]
+
+
* [[!wikipedia Combinatory logic]]
* [Combinatory logic](http://plato.stanford.edu/entries/logic-combinatory/) at the Stanford Encyclopedia of Philosophy
* [[!wikipedia SKI combinatory calculus]]
* [[!wikipedia B,C,K,W system]]
- <!-- Jeroen Fokker, The Systematic Construction of a One-combinator Basis for Lambda-Terms. Formal Aspects of Computing 4 (1992), pp. 776-780
- http://people.cs.uu.nl/jeroen/article/combinat/combinat.ps -->
-* [Chris Barker's Iota and Jot](http://semarch.linguistics.fas.nyu.edu/barker/Iota/)
+* Jeroen Fokker, "The Systematic Construction of a One-combinator Basis for Lambda-Terms" <cite>Formal Aspects of Computing</cite> 4 (1992), pp. 776-780.
+ <http://people.cs.uu.nl/jeroen/article/combinat/combinat.ps>
+* [Chris Barker's Iota and Jot](http://semarch.linguistics.fas.nyu.edu/barker/Iota/)<p>
+
+## Evaluation Order ##
+
+* [[!wikipedia Evaluation strategy]]
+* [[!wikipedia Eager evaluation]]
+* [[!wikipedia Lazy evaluation]]
+* [[!wikipedia Strict programming language]]
+
+## Confluence, Normalization, Undecidability ##
+
* [[!wikipedia Church-Rosser theorem]]
* [[!wikipedia Normalization property]]
* [[!wikipedia Turing completeness]]<p>
* [Scooping the Loop Snooper](http://www.cl.cam.ac.uk/teaching/0910/CompTheory/scooping.pdf), a proof of the undecidability of the halting problem in the style of Dr Seuss by Geoffrey K. Pullum
-* [[!wikipedia Church encoding]]
-
-##[[Learning Scheme]]##
## Recursion and the Y Combinator ##
* [The Y Combinator](http://www.ece.uc.edu/~franco/C511/html/Scheme/ycomb.html)
* [The Y Combinator](http://dangermouse.brynmawr.edu/cs245/ycomb_jim.html) derives the applicative-order Y-combinator from scratch, in Scheme. This derivation is similar in flavor to the derivation found in The Little Schemer, but uses a slightly different starting approach...
-## Evaluation Order ##
-
-* [[!wikipedia Evaluation strategy]]
-* [[!wikipedia Eager evaluation]]
-* [[!wikipedia Lazy evaluation]]
-* [[!wikipedia Strict programming language]]
-
## Types ##