4. Maintain, assert, aver, allege, hold, state all mean to express an opinion, judgment, or position. Maintain carries the implications of both firmness and persistence in declaring or supporting a conviction: She maintained her client's innocence even in the face of damaging evidence. Assert suggests assurance, confidence, and sometimes aggressiveness in the effort to persuade others to agree with or accept one's position: He asserted again and again the government's right to control the waterway. Aver, like assert, implies confident declaration and sometimes suggests a firmly positive or peremptory tone; in legal use aver means “to allege as fact”: to aver that the evidence is incontrovertible. Allege indicates a statement without evidence to support it, and thus can imply doubt as to the validity or accuracy of an assertion: The official is alleged to have been unaware of the crime. Hold means simply to have or express a conviction or belief: We hold these truths to be self-evident; She held that her rights had been violated. State usually suggests a declaration that is forthright and unambiguous: He stated his reasons in clear, simple language.

Did you mean unattainable?