all possible alignments

[vinaychetnani]

As given in the Alex Graves CTC paper, we sum over probabilities of all the possible alignments using dynamic programming which gives us certain transcription. In code and in tensorflow documentation it is not explicitly mentioned that where this part is happening. Could you help me here and tell me in which of the following functions, this DP thing is happening:

1. tf.nn.ctc_loss
2. tf.nn.ctc_beam_search_decoder
3. tf.nn.ctc_greedy_decoder