隐马尔可夫链模型和例程（包括前向、jASLLYg后向算法、Viterbi解码以及为了减少概率数值计算误差编写的对数saWeYvm运算程序）-Hidden Markov chain model and routines (including forward, backward jASLLYg algorithm, Viterbi decoding, and in order to reduce the probability of numerical computation error of the preparation of the logarithm of the saWeYvm computing program)