Syntax for an if statement with calculation contexts

Hello -

I'm looking for some syntax help.  I don't know how to structure the syntax to give me a new field that will indicate if a student has taken BIO-157 with a passing grade before they took BIO-263.

I was guessing it should be something like this but then of course there is no 'when' clause available.

=IF ([Enrollment Start Date]) When ([Enrolled Course Name] = "BIO-157" and [Passing Grade]="Yes") FOREACH ([Enrolled Academic Credit Id])

< ([Enrollment Start Date] When ([Enrolled Course Name] = "BIO-263") FOREACH ([Enrolled Academic Credit Id])

then "Yes" Else "No"

Thanks for any help possible!