let m be non empty Element of NAT ; for Z being set
for f being PartFunc of (REAL m),REAL
for g being PartFunc of (REAL-NS m),REAL st f = g holds
( ( Z c= dom f & f is_continuous_on Z ) iff g is_continuous_on Z )
let Z be set ; for f being PartFunc of (REAL m),REAL
for g being PartFunc of (REAL-NS m),REAL st f = g holds
( ( Z c= dom f & f is_continuous_on Z ) iff g is_continuous_on Z )
let f be PartFunc of (REAL m),REAL; for g being PartFunc of (REAL-NS m),REAL st f = g holds
( ( Z c= dom f & f is_continuous_on Z ) iff g is_continuous_on Z )
let g be PartFunc of (REAL-NS m),REAL; ( f = g implies ( ( Z c= dom f & f is_continuous_on Z ) iff g is_continuous_on Z ) )
assume AS:
f = g
; ( ( Z c= dom f & f is_continuous_on Z ) iff g is_continuous_on Z )
assume P1:
g is_continuous_on Z
; ( Z c= dom f & f is_continuous_on Z )
hence
Z c= dom f
by AS, NFCONT_1:def 8; f is_continuous_on Z
let x0 be Element of REAL m; PDIFF_9:def 2 ( x0 in Z implies f | Z is_continuous_in x0 )
assume P3:
x0 in Z
; f | Z is_continuous_in x0
reconsider y0 = x0 as Point of (REAL-NS m) by REAL_NS1:def 4;
g | Z is_continuous_in y0
by P3, P1, NFCONT_1:def 8;
hence
f | Z is_continuous_in x0
by AS, NFCONT_4:21; verum