Why Writing operation is decomposed into two parts "an erase followed by an add"?

[ylqfp]

The paper said:
"Taking inspiration from the input and forget gates in LSTM, we decompose each write into two parts: an erase followed by an add".
Why?
Thanks!

[shawntan]

The LSTM has the same idea of 'forgetting' and then adding the new input. That was what was meant by that line in the paper.

Just to be clear: I was in no way involved with the writing of the paper. This repo just happens to be one of the popular implementations of the NTM currently.