Use symbol mappings for more flexibility

bin/dune

bin/process.ml

bin/propositional.ml

bin/qfo.ml

bin/tptp.ml

lib/cert.ml

lib/dune

lib/encodings.ml

lib/lpCert.ml

lib/mappings.ml

lib/tptp.ml

test/dune

test/encoding/connectives.lp

test/encoding/depconnectives.lp

test/encoding/pcert.lp

test/propositional.t

test/qfo.json

test/qfo.t

test/tptp.t