theorem :: XPRIMET1:36
for k being Nat
for p being Prime st p * p <= k & k < 4489 & not p = 2 & not p = 3 & not p = 5 & not p = 7 & not p = 11 & not p = 13 & not p = 17 & not p = 19 & not p = 23 & not p = 29 & not p = 31 & not p = 37 & not p = 41 & not p = 43 & not p = 47 & not p = 53 & not p = 59 holds
p = 61