Before revision:  The main idea is to reduce the stiffness of the problem by subtracting to the standard stiffness bilinear form a least-squares penalty on the gradient jumps across the mesh interfaces  .
After revision:  The main idea is to reduce the stiffness of the problem by subtracting to the standard stiffness bilinear form a least-squares penalty on the gradient jumps across the mesh interfaces from the standard stiffness bilinear form .