A seat for a chair comprises a frame comprising spaced apart side members with inboard edges defining an opening therebetween. With some of the described techniques, invocation stubs are generated by a compiler and those stubs bridge a logical arrangement of data parallel computations to the actual physical arrangement of a target data parallel hardware for that data parallel computation. The golf club head has a center of gravity located less than 1. TRA requires a small receiver to be placed at a point of desired focus.