simple msup: 10 20

msup, high 2nd arg: 10 nYrsPerGeneration × log 50,000,000 - log 15,000 years

msup, very high mfenced in 2nd arg: 10 log 50,000,000 50,000,000 log 50,000,000 50,000,000 years

msup, mfenced only as 2nd arg: 10 2