For the proof generator, we use the pretrained
BART (Large) model (Lewis et al., 2020) and
fine-tune it using the heuristically annotated data
from Section 4. During prediction, the search
spaces for the claim and evidence are populated
using two separate tries. We add all possible
subsequences of the claim and evidence, each
with one to seven words, into the respective tries.
The default configuration takes the concatenation
of a claim and all the retrieved evidence together
as a single input, separated by a delimiter.
ProoFVer- Natural Logic Theorem Proving for Fact Verification