sixDoFRigidBodyMotion → sixDoFSolver Relation

File in src/rigidBodyMotion/sixDoFRigidBodyMotion/sixDoFRigidBodyMotion	Includes file in src/rigidBodyMotion/sixDoFRigidBodyMotion/sixDoFSolvers/sixDoFSolver
sixDoFRigidBodyMotion.C	sixDoFSolver.H