1. A system for spell correction and tokenization of natural language, said system comprising: an artificial recurrent neural network architecture of long short-term memory (LSTM) cells configured to generate: (i) variable length character level output streams (CLOS) for system fed variable length character level input streams (CLIS) and (ii) variable length tagged tokens output streams (TTOS) for system fed variable length dialog utterance input streams (DUIS); a first computer readable medium including instructions for an auto-encoder for injecting random character level modifications to the variable length CLIS, wherein the characters include a space-between-token character; a second computer readable medium including instructions for a weakly supervised training mechanism for feeding to said artificial recurrent neural network variable length DUIS, with respective correctly tagged variable length TTOS, as initial input training data, and for adjusting said recurrent neural network to learn correct variable length TTOS, by generating, and suggesting for system curator tagging correctness feedback, additional variable length DUIS, with respective variable length TTOS, as tagged by said recurrent neural network; wherein correct tagging of the suggested additional variable length DUIS improves the capability of said recurrent neural network to refine the decision boundaries between correctly and incorrectly tagged inputs and to more correctly tag following system fed variable length DUIS; and wherein variable length CLOS generated by said artificial neural network for variable length CLIS, are fed as variable length DUIS to said artificial recurrent neural network; and a third computer readable medium including instructions for an unsupervised training mechanism for adjusting said neural network to learn correct variable length CLOS, wherein correct variable length CLOS need to be similar to respective original variable length CLIS prior to random character level modifications.