Trivial formal deformation
= Trivial formal deformation
A <formal associative deformation> is trivial if a $k[[t]]$-linear <automorphism> continuous for the <adic topology> $T=\operatorname{id}\pmod t$ fixing the identity transports the deformed multiplication to the original one. This is equivalence by a formal change of coordinates, stronger than merely an abstract <algebra isomorphism> between unspecified middle terms.