Since all logical formulae can be converted into an equivalent formula in conjunctive normal form, proofs are often based on the assumption that all formulae are CNF.
In most fields, a canonical form specifies a "unique" representation for every object, while a normal form simply specifies its form, without the requirement of uniqueness.
When a theorem is proven, the system produces a verifiable proof, which validates both the clausification phase and the refutation of the conjunctive normal form.
