@jeremyjkun@mattecapu As for the Yoneda abstraction itself, the noise e used in LWE comes from the element f' in Definition 3.1. Informally, imagine that f' is something like f+e. The other noisy component is given by the set R indexing the encryption functions E
@jeremyjkun@mattecapu The general formula for the cyphertext space is given in Definition 4.15 and takes the from r(m)+cs+e. As mentioned at the end, the system relies on RLWE.