  Interactive proofs are often considered as costs of formal modelling
activity. In an incremental development environment such as the Rodin platform
for Event-B, information from proof attempts is important input for adapting
the model. This paper considers the idea of using interactive proofs to
"improve" the model, in particular, to convert them into automatic ones. We
propose to lift some essential proof information from the interactive proofs
into the model as what we called proof hints. In particular, proof hints are
not only for the purpose of proofs: it helps to understand the formal models
better.
