Rectification is available if the parties intended to give effect to the whole of an antecedent agreement in the written contract and, by common mistake, they failed to do so.[2] However, the existence of an antecedent agreement is not essential to the grant of relief by way of rectification.[2] It may be granted in cases in which the instrument sought to be rectified constitutes the only agreement between the parties but does not reflect their common intention.[3] The plaintiff needs to advance 'convincing proof' that the written contract does not embody the final intention of the parties. The omitted ingredient must be capable of such proof in clear and precise terms.[4]