Rumelhart, Hinton & Williams, Learning representations by back-propagating errors, Nature 1986 · fig. 5, p. 535

The Unrolled Recurrent NetAn iterative net, the layered net it equals, and back-propagation through time

phase

The iterative net one copy of each unit, its states kept as a history

The equivalent layered net one layer per step, each weight once between every two layers

Each set of corresponding weights

The error going back size of δ at each step, log scale

Training every case, all steps of each

Run it longer