let OAS be OAffinSpace; :: thesis: for p, q, x being Element of OAS
for f being Permutation of the carrier of OAS st f is dilatation & f . p = p & Mid q,p,f . q & not LIN p,q,x holds
Mid x,p,f . x
let p, q, x be Element of OAS; :: thesis: for f being Permutation of the carrier of OAS st f is dilatation & f . p = p & Mid q,p,f . q & not LIN p,q,x holds
Mid x,p,f . x
let f be Permutation of the carrier of OAS; :: thesis: ( f is dilatation & f . p = p & Mid q,p,f . q & not LIN p,q,x implies Mid x,p,f . x )
assume that
A1:
f is dilatation
and
A2:
f . p = p
and
A3:
Mid q,p,f . q
and
A4:
not LIN p,q,x
; :: thesis: Mid x,p,f . x
p,x '||' p,f . x
by A1, A2, Th51;
then A5:
LIN p,x,f . x
by DIRAF:def 5;
q,x '||' f . q,f . x
by A1, Th51;
then
q,x '||' f . x,f . q
by DIRAF:27;
hence
Mid x,p,f . x
by A3, A4, A5, PASCH:13; :: thesis: verum