let m be non zero Nat; for x being Point of (REAL-NS 1)
for a being Real
for i being Nat st 1 <= i & i <= m holds
(reproj (i,(0. (REAL-NS m)))) . (a * x) = a * ((reproj (i,(0. (REAL-NS m)))) . x)
let x be Point of (REAL-NS 1); for a being Real
for i being Nat st 1 <= i & i <= m holds
(reproj (i,(0. (REAL-NS m)))) . (a * x) = a * ((reproj (i,(0. (REAL-NS m)))) . x)
let a be Real; for i being Nat st 1 <= i & i <= m holds
(reproj (i,(0. (REAL-NS m)))) . (a * x) = a * ((reproj (i,(0. (REAL-NS m)))) . x)
let i be Nat; ( 1 <= i & i <= m implies (reproj (i,(0. (REAL-NS m)))) . (a * x) = a * ((reproj (i,(0. (REAL-NS m)))) . x) )
assume A1:
( 1 <= i & i <= m )
; (reproj (i,(0. (REAL-NS m)))) . (a * x) = a * ((reproj (i,(0. (REAL-NS m)))) . x)
consider q1 being Element of REAL , z1 being Element of REAL m such that
A2:
( x = <*q1*> & z1 = 0. (REAL-NS m) & (reproj (i,(0. (REAL-NS m)))) . x = (reproj (i,z1)) . q1 )
by PDIFF_1:def 6;
consider q12 being Element of REAL , z12 being Element of REAL m such that
A3:
( a * x = <*q12*> & z12 = 0. (REAL-NS m) & (reproj (i,(0. (REAL-NS m)))) . (a * x) = (reproj (i,z12)) . q12 )
by PDIFF_1:def 6;
A4:
0. (REAL-NS m) = 0* m
by REAL_NS1:def 4;
reconsider qq1 = <*q1*> as Element of REAL 1 by FINSEQ_2:98;
a * x = a * qq1
by A2, REAL_NS1:3;
then A5:
a * x = <*(a * q1)*>
by RVSUM_1:47;
a * ((reproj (i,(0. (REAL-NS m)))) . x) =
a * ((reproj (i,(0* m))) . q1)
by A2, A4, REAL_NS1:3
.=
(reproj (i,(0* m))) . (a * q1)
by A1, Th15
;
hence
(reproj (i,(0. (REAL-NS m)))) . (a * x) = a * ((reproj (i,(0. (REAL-NS m)))) . x)
by A5, A3, A4, FINSEQ_1:76; verum