What is the test for cross examination of evidence that may not ultimately be admissible?

There are many kinds of evidence that may not be ultimately admissible at a hearing but may properly be the subject of cross examination. Hearsay evidence or similar fact evidence are examples. Having regard to Justice Perell’s analysis in Ontario v. Rothman’s, supra, I am conscious of the fact that cross examination may be narrower than discovery. Nevertheless it is perfectly permissible to seek admissions on cross examination and it is perfectly reasonable to unearth evidence that may or may not ultimately be admissible. It will only be evidence that cannot be admissible under any circumstances that will be irrelevant.[5]