let AS be AffinSpace; for X being Subset of AS
for a, p being POINT of (IncProjSp_of AS)
for A being LINE of (IncProjSp_of AS) st A = [X,1] & X is being_line & p on A & a on A & a <> p & p is not Element of AS holds
a is Element of AS
let X be Subset of AS; for a, p being POINT of (IncProjSp_of AS)
for A being LINE of (IncProjSp_of AS) st A = [X,1] & X is being_line & p on A & a on A & a <> p & p is not Element of AS holds
a is Element of AS
let a, p be POINT of (IncProjSp_of AS); for A being LINE of (IncProjSp_of AS) st A = [X,1] & X is being_line & p on A & a on A & a <> p & p is not Element of AS holds
a is Element of AS
let A be LINE of (IncProjSp_of AS); ( A = [X,1] & X is being_line & p on A & a on A & a <> p & p is not Element of AS implies a is Element of AS )
assume that
A1:
A = [X,1]
and
A2:
X is being_line
and
A3:
p on A
and
A4:
a on A
and
A5:
a <> p
and
A6:
p is not Element of AS
; a is Element of AS
assume
a is not Element of AS
; contradiction
then
a = LDir X
by A1, A2, A4, Th34;
hence
contradiction
by A1, A2, A3, A5, A6, Th34; verum