let m, n be non empty Element of NAT ; for j, i being Element of NAT
for f being PartFunc of (REAL-NS m),(REAL-NS n)
for h being PartFunc of (REAL m),(REAL n)
for x being Point of (REAL-NS m)
for z being Element of REAL m st f = h & x = z holds
((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z))
let j, i be Element of NAT ; for f being PartFunc of (REAL-NS m),(REAL-NS n)
for h being PartFunc of (REAL m),(REAL n)
for x being Point of (REAL-NS m)
for z being Element of REAL m st f = h & x = z holds
((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z))
let f be PartFunc of (REAL-NS m),(REAL-NS n); for h being PartFunc of (REAL m),(REAL n)
for x being Point of (REAL-NS m)
for z being Element of REAL m st f = h & x = z holds
((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z))
let h be PartFunc of (REAL m),(REAL n); for x being Point of (REAL-NS m)
for z being Element of REAL m st f = h & x = z holds
((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z))
let x be Point of (REAL-NS m); for z being Element of REAL m st f = h & x = z holds
((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z))
let z be Element of REAL m; ( f = h & x = z implies ((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z)) )
reconsider h1 = (proj 1,1) " as Function of REAL ,(REAL 1) by Th2;
assume that
A1:
f = h
and
A2:
x = z
; ((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z))
<>* (((proj j,n) * h) * (reproj i,z)) =
(h1 * ((proj j,n) * (h * (reproj i,z)))) * (proj 1,1)
by RELAT_1:55
.=
((h1 * (proj j,n)) * (h * (reproj i,z))) * (proj 1,1)
by RELAT_1:55
.=
(h1 * (proj j,n)) * ((h * (reproj i,z)) * (proj 1,1))
by RELAT_1:55
.=
(h1 * (proj j,n)) * (h * ((reproj i,z) * (proj 1,1)))
by RELAT_1:55
.=
(Proj j,n) * (h * ((reproj i,z) * (proj 1,1)))
by Th11
.=
(Proj j,n) * (h * (reproj i,x))
by A2, Th12
;
hence
((Proj j,n) * f) * (reproj i,x) = <>* (((proj j,n) * h) * (reproj i,z))
by A1, RELAT_1:55; verum