A carry state is an information stream that transports a representation across sequence timesteps, where later operations can modify or use it. section 13.3.2
Within an LSTM cell, the carry state:
- Combines with the input and recurrent connection to influence the next output and next state. section 13.3.2
- Updates through three transformations associated with the input, forget, and candidate paths. section 13.3.2
- Uses the forget path to scale existing information and the input and candidate paths to add new information. section 13.3.2
Carry update
The update can be written as c_t+1 = i_t * k_t + c_t * f_t. The weights learn how these operations behave, so their intuitive roles are not fixed. section 13.3.2
Figure 13.8 Going from a SimpleRNN to an LSTM: adding a carry track
Compare the SimpleRNN cell with the added carry track to visualize how LSTM information flow expands across timesteps. section 13.3.2




