Additionally, we define rules to assign a NatOp
for named entities using Wikidata. Here, aliases
of an entity are marked with an equivalence
NatOp (≡), as shown in third triple in Figure 1.
Further, we manually assign NatOps to the 500
most frequently occurring Wikidata relations in
the aligned training data. For instance, as shown
in Figure 5, the entities ‘The Trial’ and ‘novel’
have the relation ‘genre’. A claim span containing
‘The Trial’, when substituted with an evidence
span containing ‘novel’, would result in a general-
isation of the claim, and hence will be assigned the
reverse entailment NatOp ((cid:11)). A substitution in
the reverse direction would be assigned a forward
entailment NatOp ((cid:9)), indicating specialization.
The KB relations we annotated occur between
the entities linked in Wikidata, and they do not

Figure 5: Entities and their relations in Wikidata.
ProoFVer- Natural Logic Theorem Proving for Fact Verification