deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
as अस् plus a अ makes o ओ. This happens because of rules sasajuSoruH, atororapl..., AdguNaH, and eGaHpadAnt....
Before the other vowels, as अस् turns into a:: अ. This happens because of bhobhagoagh... and lopazzAkaly....
Back to sandhi tables.
Other rules allow ay अय् instead of a:: अ — this is used when talking, but not in writing. See bhobhagoagh..., vyorlaghupray....