defpred S1[ Nat] means subdivision ($1,(center_of_mass V),Kv) is non void Subdivision of Kv;
A2:
for k being Nat st S1[k] holds
S1[k + 1]
proof
let k be
Nat;
( S1[k] implies S1[k + 1] )
assume
S1[
k]
;
S1[k + 1]
then reconsider P =
subdivision (
k,
(center_of_mass V),
Kv) as non
void Subdivision of
Kv ;
A3:
(
|.P.| = |.Kv.| &
[#] P = [#] Kv )
by Th10, SIMPLEX0:64;
k in NAT
by ORDINAL1:def 12;
then subdivision (
(k + 1),
(center_of_mass V),
Kv) =
subdivision (1,
(center_of_mass V),
(subdivision (k,(center_of_mass V),Kv)))
by SIMPLEX0:63
.=
subdivision (
(center_of_mass V),
P)
by SIMPLEX0:62
.=
BCS P
by A1, A3, Def5
;
hence
S1[
k + 1]
by Th14;
verum
end;
Kv = subdivision (0,(center_of_mass V),Kv)
by SIMPLEX0:61;
then A4:
S1[ 0 ]
by Th11;
for k being Nat holds S1[k]
from NAT_1:sch 2(A4, A2);
hence
subdivision (n,(center_of_mass V),Kv) is non void Subdivision of Kv
; verum