let a, b, c be Real; for f, g, F being Function of REAL,REAL st a <= b & b <= c & f is continuous & g is continuous & F = (f | [.a,b.]) +* (g | [.b,c.]) & f . b = g . b holds
F is continuous
let f, g, F be Function of REAL,REAL; ( a <= b & b <= c & f is continuous & g is continuous & F = (f | [.a,b.]) +* (g | [.b,c.]) & f . b = g . b implies F is continuous )
assume that
A1:
( a <= b & b <= c )
and
A2:
( f is continuous & g is continuous )
and
A3:
F = (f | [.a,b.]) +* (g | [.b,c.])
and
A4:
f . b = g . b
; F is continuous
F = F | [.a,c.]
by Th25, A1, A3;
hence
F is continuous
by Lm22b1, A1, A2, A3, A4; verum