let M be empty-yielding Conditional_Probability Matrix of REAL; for i, j being Nat st [i,j] in Indices M holds
M * (i,j) <= 1
A1:
for i, j being Nat st [i,j] in Indices M holds
M * (i,j) >= 0
by Def6;
A2:
for i being Nat st i in dom M holds
for j being Nat st j in dom (M . i) holds
(M . i) . j <= 1
let i, j be Nat; ( [i,j] in Indices M implies M * (i,j) <= 1 )
assume A5:
[i,j] in Indices M
; M * (i,j) <= 1
A6:
ex p1 being FinSequence of REAL st
( p1 = M . i & M * (i,j) = p1 . j )
by A5, MATRIX_0:def 5;
i in Seg (len M)
by A5, Th12;
then A7:
i in dom M
by FINSEQ_1:def 3;
j in Seg (width M)
by A5, Th12;
then
j in Seg (len (M . i))
by A7, MATRIX_0:36;
then
j in dom (M . i)
by FINSEQ_1:def 3;
hence
M * (i,j) <= 1
by A2, A7, A6; verum