1. A method of statistical inference, comprising: (a) providing a computing platform comprising a Central Processing Unit (CPU) and a Graphical Processing Unit (GPU); (b) generating a one or more level arc-based recognition network for a problem, comprising: a plurality of epsilon arcs; a plurality of non-epsilon arcs; a plurality of states that may be interconnected by one or more epsilon or non-epsilon arcs; and (c) selectively flattening the levels of the recognition network so as to improve inference speed; (d) wherein the recognition network is executed on the CPU and the GPU.