ALV - 2 is reserve guarantee. Look closer at my example. I never mention ALV.

PWA 3.G.1 - "An end-of-month (EOM) partial payment on the last business day of the corresponding calendar month in the amount of one-half of the reserve guarantee at his composite hourly pay rate as of the date of the payment"

New Hire Pilot Guide - Page 18 under the definition of Paid in Advance - "You are paid a flight advance for ½ of the current bid period's reserve line guarantee at your composite hourly rate on the last day of the current month."

I've done the math quite a few times so I can verify these statements above.

Of note, the EOM Check uses the lesser rate of your fleet if yours have multiple pay rates for different size aircraft so use it in figuring the math.