query.md

### Query Encoding

Let's start by exploring SPLADE's query encoder. The query encoder is a `Q→Q` (query rewriting, query-to-query) transformer, and can be used in pipelines accordingly.
It maps a query string into [MatchOp](https://terrier-core.readthedocs.io/en/latest/querylanguage.html#matching-op-query-language) query with terms from the
query re-weighted and weighted expansion terms added.

<div class="pipeline">
  <div class="df" title="Query Frame">Q</div>
  <div class="transformer attn" title="SPLADE Query Transformer">SPLADE</div>
  <div class="df" title="Query Frame">Q</div>
</div>