In this paper the deductive systems [special characters omitted] and [special characters omitted] from [Tarski, Givant (1987)] are shown to be equipollent. Following [Tarski, Givant (1987)], a third deductive system, [special characters omitted], is defined. It is then noted that [special characters omitted] is an extension of both [special characters omitted] and [special characters omitted], thus showing that [special characters omitted] and [special characters omitted] are no stronger than [special characters omitted]. Finally two Translation Mappings from G : [special characters omitted] → [special characters omitted] and H : [special characters omitted] → [special characters omitted] are defined. These mappings show that [special characters omitted] is no stronger than either [special characters omitted] or [special characters omitted]. Therefore we conclude that, as they are both equipollent to a relative extension, [special characters omitted] and [special characters omitted] are equipollent.