1 Groups, semigroups, monoids, and computers - Joe Marshall (funcall.blogspot.com) 3 points by soegaard 1553 days ago

2 Tail recursion and fold-left - Joe Marshall (funcall.blogspot.com) 3 points by soegaard 940 days ago

3 100% Coverage - Joe Marshall (funcall.blogspot.com) 2 points by soegaard 1583 days ago

4 A polyglot program puzzle - Joe Marshall (funcall.blogspot.com) 2 points by soegaard 1521 days ago