If you can't understand it, ask for a meeting with the HR personnel of UBC to explain it, or her faculty union if there one. Or ask if they have pre-retirement seminars that cover this. You can also ask for an estimate of her pension, but it will usually be an estimate only of the pension she has earned to date, because it is too difficult to predict what her future average earnings will be.My spouse has been employed at the University of British Columbia for over 10 years and they have a defined benefit pension for staff. Their info page is here: http://www.pensions.ubc.ca/staff/glance.html.
I honestly can't understand a darn thing about how the pension works.
Is there a good site that explains how pensions work?
There is no one site that explains everything about pensions because they all have different features. In the plan you refer to, the first formula contains an adjustment for CPP. This is called "coordination of benefits with CPP" and is common for large pension plans. Something changed in 2009, and they are using a different formula for service earned after that date. I presume the university negotiated a different pension contribution and benefit formula recently. It is hard to believe that your spouse would not have received information from both the university and her bargaining group on the reason behind such an important personnel issue.
Other adjustments in the document tell you how the pension is adjusted if you retire before 65. This too is standard practice, only the details change. A pension plan is calculated actuarially for a specific retirement age (usually 65), with formulas for changing the payment if you retire at a different age.