How does the Court of Appeal review a prior conviction allegation?

We review under the deferential abuse of discretion standard a trial court's failure to dismiss or strike a prior conviction allegation. (People v. Carmony (2004) 33 Cal.4th 367, 375.) Two fundamental precepts guide our appellate review. First, the appealing party bears the burden " ' "to clearly show that the sentencing decision was irrational or arbitrary. [Citation.] In the absence of such a showing, the trial court is presumed to have acted to achieve legitimate sentencing objectives, and its discretionary determination to impose a particular sentence will not be set aside on review." ' [Citations.]" (Id. at pp. 376-377.) "Second, a ' "decision will not be reversed merely because reasonable people might disagree. 'An appellate tribunal is neither authorized nor warranted in substituting its judgment for the judgment of the trial judge.' " ' [Citation.] Taken together, these precepts establish that a trial court does not abuse its discretion unless its decision is so irrational or arbitrary that no reasonable person could agree with it." (Id. at p. 377.)