let t be Nat; for G being Go-board
for f being non constant standard special_circular_sequence st f is_sequence_on G & 1 <= t & t <= width G holds
(G * ((len G),t)) `1 >= E-bound (L~ f)
let G be Go-board; for f being non constant standard special_circular_sequence st f is_sequence_on G & 1 <= t & t <= width G holds
(G * ((len G),t)) `1 >= E-bound (L~ f)
let f be non constant standard special_circular_sequence; ( f is_sequence_on G & 1 <= t & t <= width G implies (G * ((len G),t)) `1 >= E-bound (L~ f) )
E-min (L~ f) in rng f
by SPRECT_2:45;
then consider x being object such that
A1:
x in dom f
and
A2:
f . x = E-min (L~ f)
by FUNCT_1:def 3;
reconsider x = x as Nat by A1;
assume
f is_sequence_on G
; ( not 1 <= t or not t <= width G or (G * ((len G),t)) `1 >= E-bound (L~ f) )
then consider i, j being Nat such that
A3:
[i,j] in Indices G
and
A4:
f /. x = G * (i,j)
by A1, GOBOARD1:def 9;
A5:
( 1 <= i & i <= len G )
by A3, MATRIX_0:32;
assume A6:
( 1 <= t & t <= width G )
; (G * ((len G),t)) `1 >= E-bound (L~ f)
( 1 <= j & j <= width G )
by A3, MATRIX_0:32;
then
( E-bound (L~ f) = (E-min (L~ f)) `1 & (G * ((len G),t)) `1 >= (G * (i,j)) `1 )
by A6, A5, Th18, EUCLID:52;
hence
(G * ((len G),t)) `1 >= E-bound (L~ f)
by A1, A2, A4, PARTFUN1:def 6; verum