let f1, f2 be Function of (pi_1 T,x1),(pi_1 T,x0); ( ( for Q being Loop of x1 holds f1 . (Class (EqRel T,x1),Q) = Class (EqRel T,x0),((P + Q) + (- P)) ) & ( for Q being Loop of x1 holds f2 . (Class (EqRel T,x1),Q) = Class (EqRel T,x0),((P + Q) + (- P)) ) implies f1 = f2 )
assume that
A9:
for Q being Loop of x1 holds f1 . (Class (EqRel T,x1),Q) = Class (EqRel T,x0),((P + Q) + (- P))
and
A10:
for Q being Loop of x1 holds f2 . (Class (EqRel T,x1),Q) = Class (EqRel T,x0),((P + Q) + (- P))
; f1 = f2
for x being Element of (pi_1 T,x1) holds f1 . x = f2 . x
hence
f1 = f2
by FUNCT_2:113; verum