http://www.eimacs.com

This is an online training for logic and computer programming.
My son did the Introduction to Logic over the summer when he was twelve. This was a prerequisite for a group class that he took over the school year. At twelve, he was among the oldest students from the group, however, he did have an easier time with it than most too.

The below quote is from their FAQs section;

Quote
What classes must my child have taken to be ready for Advanced Mathematical Logic?
Being ready for Introduction to Logic I, the first course in the track, has little to do with what specific courses your child has taken, but has everything to do with your child's aptitude for mathematical thinking and reading comprehension.
How do I know if my child is ready for the course? How do we prove to IMACS that my child is ready?
IMACS has a free, online aptitude test that your child can take. To be accepted into the course, a student must pass the aptitude test. You can register online for the aptitude test. It is free and there is no commitment or obligation. After your child completes the aptitude test, IMACS will contact you with the results.