The rule of bal is to place the second expression in the position of the first. Yet the existence of this linguistic function does not by itself cancel a legal consequence already produced by the first words.
In reports, correction may be effective. In performative acts, one must consider the occurrence of the first effect and the continuing suitability of the legal subject. In admissions, one must distinguish an amended description of the same claim from a separate obligation.
Language, speech act, and legal circumstances must be read together.