let n be Nat; for M1, M2 being Matrix of n, REAL st M1 is Positive holds
M2 - M1 is_less_than M2
let M1, M2 be Matrix of n, REAL ; ( M1 is Positive implies M2 - M1 is_less_than M2 )
assume A1:
M1 is Positive
; M2 - M1 is_less_than M2
A2:
Indices M1 = [:(Seg n),(Seg n):]
by MATRIX_1:25;
A3:
width M1 = width M2
by Lm1;
A4:
Indices (M2 - M1) = [:(Seg n),(Seg n):]
by MATRIX_1:25;
A5:
( Indices M2 = [:(Seg n),(Seg n):] & len M1 = len M2 )
by Lm1, MATRIX_1:25;
for i, j being Nat st [i,j] in Indices (M2 - M1) holds
(M2 - M1) * i,j < M2 * i,j
proof
let i,
j be
Nat;
( [i,j] in Indices (M2 - M1) implies (M2 - M1) * i,j < M2 * i,j )
assume A6:
[i,j] in Indices (M2 - M1)
;
(M2 - M1) * i,j < M2 * i,j
then
M1 * i,
j > 0
by A1, A2, A4, Def1;
then
(M2 * i,j) - (M1 * i,j) < M2 * i,
j
by XREAL_1:46;
hence
(M2 - M1) * i,
j < M2 * i,
j
by A4, A5, A3, A6, Th3;
verum
end;
hence
M2 - M1 is_less_than M2
by Def5; verum