let V be RealLinearSpace; for w, y being VECTOR of st Gen w,y holds
for p, q, u, v, v' being VECTOR of
for A being Real st p,q,u,v are_DTr_wrt w,y & p <> q & A = ((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " ) & v' = u + (A * (p - q)) holds
v = v'
let w, y be VECTOR of ; ( Gen w,y implies for p, q, u, v, v' being VECTOR of
for A being Real st p,q,u,v are_DTr_wrt w,y & p <> q & A = ((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " ) & v' = u + (A * (p - q)) holds
v = v' )
assume A1:
Gen w,y
; for p, q, u, v, v' being VECTOR of
for A being Real st p,q,u,v are_DTr_wrt w,y & p <> q & A = ((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " ) & v' = u + (A * (p - q)) holds
v = v'
let p, q, u, v, v' be VECTOR of ; for A being Real st p,q,u,v are_DTr_wrt w,y & p <> q & A = ((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " ) & v' = u + (A * (p - q)) holds
v = v'
let A be Real; ( p,q,u,v are_DTr_wrt w,y & p <> q & A = ((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " ) & v' = u + (A * (p - q)) implies v = v' )
assume that
A2:
p,q,u,v are_DTr_wrt w,y
and
A3:
p <> q
and
A4:
A = ((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " )
and
A5:
v' = u + (A * (p - q))
; v = v'
A6:
PProJ w,y,(p - q),(p - q) <> 0
by A1, A3, Th37;
A7: PProJ w,y,(p - q),(A * (p - q)) =
(((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " )) * (PProJ w,y,(p - q),(p - q))
by A1, A4, Th33
.=
((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * (((PProJ w,y,(p - q),(p - q)) " ) * (PProJ w,y,(p - q),(p - q)))
.=
((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * 1
by A6, XCMPLX_0:def 7
.=
(PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))
;
set s = p # q;
set X = PProJ w,y,(p - q),((v' # u) - (p # q));
2 * (PProJ w,y,(p - q),((v' # u) - (p # q))) =
2 * ((PProJ w,y,(p - q),(v' # u)) - (PProJ w,y,(p - q),(p # q)))
by A1, Th32
.=
(2 * (PProJ w,y,(p - q),(v' # u))) - (2 * (PProJ w,y,(p - q),(p # q)))
.=
((PProJ w,y,(p - q),v') + (PProJ w,y,(p - q),u)) - (2 * (PProJ w,y,(p - q),(p # q)))
by A1, Th36
.=
((PProJ w,y,(p - q),v') + (PProJ w,y,(p - q),u)) - ((PProJ w,y,(p - q),p) + (PProJ w,y,(p - q),q))
by A1, Th36
.=
((PProJ w,y,(p - q),(u + (A * (p - q)))) + (PProJ w,y,(p - q),u)) - (PProJ w,y,(p - q),(p + q))
by A1, A5, Th32
.=
(((PProJ w,y,(p - q),u) + (PProJ w,y,(p - q),(A * (p - q)))) + (PProJ w,y,(p - q),u)) - (PProJ w,y,(p - q),(p + q))
by A1, Th32
;
then
q,p,p # q,v' # u are_Ort_wrt w,y
by A1, A7, Th35;
then
p # q,v' # u,q,p are_Ort_wrt w,y
by Lm5;
then A8:
p # q,v' # u,p,q are_Ort_wrt w,y
by Lm4;
set Y = PProJ w,y,(v' - u),((v' # u) - (p # q));
A9:
v' - u = A * (p - q)
by A5, RLSUB_2:78;
1 * (v' - u) =
(u + (A * (p - q))) - u
by A5, RLVECT_1:def 9
.=
A * (p - q)
by RLSUB_2:78
;
then
( q,p // u,v' or q,p // v',u )
by ANALMETR:18;
then A10:
( p,q // u,v' or p,q // v',u )
by ANALOAF:21;
A11: PProJ w,y,(A * (p - q)),(A * (p - q)) =
A * (PProJ w,y,(p - q),(A * (p - q)))
by A1, Th33
.=
A * ((((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * ((PProJ w,y,(p - q),(p - q)) " )) * (PProJ w,y,(p - q),(p - q)))
by A1, A4, Th33
.=
A * (((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * (((PProJ w,y,(p - q),(p - q)) " ) * (PProJ w,y,(p - q),(p - q))))
.=
A * (((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u))) * 1)
by A6, XCMPLX_0:def 7
.=
A * ((PProJ w,y,(p - q),(p + q)) - (2 * (PProJ w,y,(p - q),u)))
;
2 * (PProJ w,y,(v' - u),((v' # u) - (p # q))) =
2 * ((PProJ w,y,(v' - u),(v' # u)) - (PProJ w,y,(v' - u),(p # q)))
by A1, Th32
.=
(2 * (PProJ w,y,(v' - u),(v' # u))) - (2 * (PProJ w,y,(v' - u),(p # q)))
.=
((PProJ w,y,(v' - u),v') + (PProJ w,y,(v' - u),u)) - (2 * (PProJ w,y,(v' - u),(p # q)))
by A1, Th36
.=
((PProJ w,y,(v' - u),v') + (PProJ w,y,(v' - u),u)) - ((PProJ w,y,(v' - u),p) + (PProJ w,y,(v' - u),q))
by A1, Th36
.=
((PProJ w,y,(v' - u),(u + (A * (p - q)))) + (PProJ w,y,(v' - u),u)) - (PProJ w,y,(v' - u),(p + q))
by A1, A5, Th32
.=
(((PProJ w,y,(v' - u),u) + (PProJ w,y,(v' - u),(A * (p - q)))) + (PProJ w,y,(v' - u),u)) - (PProJ w,y,(v' - u),(p + q))
by A1, Th32
;
then A12: 2 * (PProJ w,y,(v' - u),((v' # u) - (p # q))) =
(((PProJ w,y,(A * (p - q)),u) + ((A * (PProJ w,y,(p - q),(p + q))) - (A * (2 * (PProJ w,y,(p - q),u))))) + (PProJ w,y,(A * (p - q)),u)) - (PProJ w,y,(A * (p - q)),(p + q))
by A9, A11
.=
(((PProJ w,y,(A * (p - q)),u) + ((PProJ w,y,(A * (p - q)),(p + q)) - (2 * (A * (PProJ w,y,(p - q),u))))) + (PProJ w,y,(A * (p - q)),u)) - (PProJ w,y,(A * (p - q)),(p + q))
by A1, Th33
.=
(((PProJ w,y,(A * (p - q)),u) + ((PProJ w,y,(A * (p - q)),(p + q)) - (2 * (PProJ w,y,(A * (p - q)),u)))) + (PProJ w,y,(A * (p - q)),u)) - (PProJ w,y,(A * (p - q)),(p + q))
by A1, Th33
.=
0
;
then
u,v',p # q,v' # u are_Ort_wrt w,y
by A1, Th35;
then
p # q,v' # u,u,v' are_Ort_wrt w,y
by Lm5;
then
p # q,v' # u,v',u are_Ort_wrt w,y
by Lm4;
then
( p,q,p # q,u # v' are_Ort_wrt w,y & u,v',p # q,u # v' are_Ort_wrt w,y & p,q,p # q,v' # u are_Ort_wrt w,y & v',u,p # q,v' # u are_Ort_wrt w,y )
by A1, A8, A12, Lm5, Th35;
then
( p,q,u,v' are_DTr_wrt w,y or p,q,v',u are_DTr_wrt w,y )
by A10, Def3;
hence
v = v'
by A1, A2, A3, Th27; verum