What is the test for corroborating evidence in a sexual assault case?

Section 1111 provides, in relevant in part: "A conviction cannot be had upon the testimony of an accomplice unless it be corroborated by such other evidence as shall tend to connect the defendant with the commission of the offense; and the corroboration is not sufficient if it merely shows the commission of the offense or the circumstances thereof." To be sufficient, corroborating evidence must, " without aid or assistance from the testimony of the accomplice, tend[ ] to connect the defendant with the crime charged. " ( People v. Rodrigues, supra, 8 Cal.4th at p. 1128, 36 Cal.Rptr.2d 235, 885 P.2d 1.) Put differently, corroborating evidence " " must relate to some act or fact which is an element of the crime[, although] it is not necessary that the corroborative evidence be sufficient in itself to establish every element of the offense charged. " " ( Ibid. ) Corroborating evidence may be circumstantial and so slight as to be " " entitled to little consideration when standing alone. " " ( Ibid. ) It " "is sufficient if it substantiates enough of the accomplice's testimony to establish his credibility." " ( Ibid. )