let R be gcdDomain; for Amp, Amp9 being AmpleSet of R
for x, y being Element of R st x,y are_canonical_wrt Amp holds
x,y are_canonical_wrt Amp9
let Amp, Amp9 be AmpleSet of R; for x, y being Element of R st x,y are_canonical_wrt Amp holds
x,y are_canonical_wrt Amp9
let x, y be Element of R; ( x,y are_canonical_wrt Amp implies x,y are_canonical_wrt Amp9 )
(1. R) * x = x
by VECTSP_1:def 8;
then A1:
1. R divides x
by Def1;
(1. R) * y = y
by VECTSP_1:def 8;
then A2:
1. R divides y
by Def1;
assume
x,y are_canonical_wrt Amp
; x,y are_canonical_wrt Amp9
then
gcd (x,y,Amp) = 1. R
by Def13;
then A3:
for z being Element of R st z divides x & z divides y holds
z divides 1. R
by Def12;
1. R in Amp9
by Def8;
then
gcd (x,y,Amp9) = 1. R
by A3, A1, A2, Def12;
hence
x,y are_canonical_wrt Amp9
by Def13; verum