let M be Matrix of 3,F_Real; for MR being Matrix of 3,REAL
for v being Element of (TOP-REAL 3)
for uf being FinSequence of F_Real
for ufr being FinSequence of REAL
for p being FinSequence of 1 -tuples_on REAL st p = M * uf & v = M2F p & len uf = 3 & uf = ufr & MR = M holds
v = MR * ufr
let MR be Matrix of 3,REAL; for v being Element of (TOP-REAL 3)
for uf being FinSequence of F_Real
for ufr being FinSequence of REAL
for p being FinSequence of 1 -tuples_on REAL st p = M * uf & v = M2F p & len uf = 3 & uf = ufr & MR = M holds
v = MR * ufr
let v be Element of (TOP-REAL 3); for uf being FinSequence of F_Real
for ufr being FinSequence of REAL
for p being FinSequence of 1 -tuples_on REAL st p = M * uf & v = M2F p & len uf = 3 & uf = ufr & MR = M holds
v = MR * ufr
let uf be FinSequence of F_Real; for ufr being FinSequence of REAL
for p being FinSequence of 1 -tuples_on REAL st p = M * uf & v = M2F p & len uf = 3 & uf = ufr & MR = M holds
v = MR * ufr
let ufr be FinSequence of REAL ; for p being FinSequence of 1 -tuples_on REAL st p = M * uf & v = M2F p & len uf = 3 & uf = ufr & MR = M holds
v = MR * ufr
let p be FinSequence of 1 -tuples_on REAL; ( p = M * uf & v = M2F p & len uf = 3 & uf = ufr & MR = M implies v = MR * ufr )
assume that
A1:
p = M * uf
and
A2:
v = M2F p
and
A3:
len uf = 3
and
A4:
uf = ufr
and
A5:
MR = M
; v = MR * ufr
consider a, b, c, d, e, f, g, h, i being Element of F_Real such that
A6:
M = <*<*a,b,c*>,<*d,e,f*>,<*g,h,i*>*>
by PASCAL:3;
uf is Element of REAL 3
by A3, EUCLID_8:2;
then
uf in REAL 3
;
then
uf in TOP-REAL 3
by EUCLID:22;
then consider t1, t2, t3 being Real such that
A7:
uf = <*t1,t2,t3*>
by EUCLID_5:1;
reconsider x = t1, y = t2, z = t3 as Element of F_Real by XREAL_0:def 1;
v = <*(((a * x) + (b * y)) + (c * z)),(((d * x) + (e * y)) + (f * z)),(((g * x) + (h * y)) + (i * z))*>
by PASCAL:8, A1, A2, A6, A7;
hence
v = MR * ufr
by A7, A4, A5, A6, PASCAL:9; verum