consider P being strict IncSpace-like IncStruct ;
take IT = IncProjStr(# the Points of P,the Lines of P,the Inc of P #); :: thesis: ( IT is with_non-trivial_lines & IT is linear & IT is up-2-rank & IT is strict )
thus
for L being LINE of IT ex A, B being POINT of IT st
( A <> B & {A,B} on L )
:: according to INCSP_1:def 8 :: thesis: ( IT is linear & IT is up-2-rank & IT is strict )
thus
IT is linear
:: thesis: ( IT is up-2-rank & IT is strict )
thus
for A, B being POINT of IT
for K, L being LINE of IT st A <> B & {A,B} on K & {A,B} on L holds
K = L
:: according to INCSP_1:def 10 :: thesis: IT is strictproof
let A,
B be
POINT of
IT;
:: thesis: for K, L being LINE of IT st A <> B & {A,B} on K & {A,B} on L holds
K = Llet K,
L be
LINE of
IT;
:: thesis: ( A <> B & {A,B} on K & {A,B} on L implies K = L )
assume A3:
(
A <> B &
{A,B} on K &
{A,B} on L )
;
:: thesis: K = L
reconsider A' =
A,
B' =
B as
POINT of
P ;
reconsider K' =
K,
L' =
L as
LINE of
P ;
(
A' <> B' &
{A',B'} on K' &
{A',B'} on L' )
by A3, Th9;
hence
K = L
by INCSP_1:def 10;
:: thesis: verum
end;
thus
IT is strict
; :: thesis: verum