let f, F be PartFunc of REAL,REAL; for I being non empty Interval
for r being Real st F is_antiderivative_of f,I holds
r (#) F is_antiderivative_of r (#) f,I
let I be non empty Interval; for r being Real st F is_antiderivative_of f,I holds
r (#) F is_antiderivative_of r (#) f,I
let r be Real; ( F is_antiderivative_of f,I implies r (#) F is_antiderivative_of r (#) f,I )
assume A1:
F is_antiderivative_of f,I
; r (#) F is_antiderivative_of r (#) f,I
then
( r (#) F is_differentiable_on_interval I & (r (#) F) `\ I = r (#) (F `\ I) )
by FDIFF_12:23;
hence
r (#) F is_antiderivative_of r (#) f,I
by A1, RFUNCT_1:49; verum