let j, n be Nat; for f being Element of REAL * st OuterVx (f,n) <> {} & j = Argmin ((OuterVx (f,n)),f,n) holds
( j in dom f & 1 <= j & j <= n & f . j <> - 1 & f . (n + j) <> - 1 )
let f be Element of REAL * ; ( OuterVx (f,n) <> {} & j = Argmin ((OuterVx (f,n)),f,n) implies ( j in dom f & 1 <= j & j <= n & f . j <> - 1 & f . (n + j) <> - 1 ) )
set IN = OuterVx (f,n);
assume
( OuterVx (f,n) <> {} & j = Argmin ((OuterVx (f,n)),f,n) )
; ( j in dom f & 1 <= j & j <= n & f . j <> - 1 & f . (n + j) <> - 1 )
then
ex i being Nat st
( i = j & i in OuterVx (f,n) & ( for k being Nat st k in OuterVx (f,n) holds
f /. ((2 * n) + i) <= f /. ((2 * n) + k) ) & ( for k being Nat st k in OuterVx (f,n) & f /. ((2 * n) + i) = f /. ((2 * n) + k) holds
i <= k ) )
by Def10;
then
ex k being Nat st
( j = k & k in dom f & 1 <= k & k <= n & f . k <> - 1 & f . (n + k) <> - 1 )
;
hence
( j in dom f & 1 <= j & j <= n & f . j <> - 1 & f . (n + j) <> - 1 )
; verum