I'm having trouble figuring out how to use Christoffel symbols. Apart from the first three terms here, I can't understand what's going on between line 3 and 4. What formulas/definitions are being used? How do you find the product of two chirstoffel symbols? Where are all the minuses coming from?
The Attempt at a Solution
It looks like the product rule is needed when three terms are multiplied together. The indices p and l seem to be interchangeable.