Figure 2.

Schematic of LSTM cell structure with an internal recurrence $c_t$ and an outer recurrence $h_t$. Cell gates are the input gate ${\mathrm{i}}_t$, input modulation gate $g_t$, forget gate $f_t$, and output gate $o_t$. In contrast to an RNN node, the current output ${𝓎}_t$ is considered equal to current hidden state $h_t$.