Hexapod walking constraints?

Hey, I’m trying to write my own code to produce the sequences. Say I want to use a tripod gait to produce my forward motion, what are the angle/coordinate constraints to produce the motion? Will the IK solve this for me? (I can arbitrarily use any x, y, z coordinate for each leg as long as it makes sense?

By the way, is this doc good for IK?
scribd.com/doc/77898721/Equa … ot-Control
I looked through it and it seems some formulas are missing in the straight walk (what are l3 and l4 for example)? If not what are some good tutorials on IK formulas?