theorem :: FINTOPO8:19

for NTX, NTY being NTopSpace
for XA being Subset of NTX
for YB being Subset of NTY
for x being Point of NTX
for y being Point of NTY
for f being Function of NTX,NTY st f is_continuous_at x & x is_adherent_point_of XA & y = f . x & YB = f .: XA holds
y is_adherent_point_of YB by Lm12;