let G2 be _Graph; for v, e being object
for w being Vertex of G2
for G1 being addAdjVertex of G2,v,e,w
for t1 being TColoring of G1
for t2 being TColoring of G2
for x, y being object st not e in the_Edges_of G2 & not v in the_Vertices_of G2 & t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) & not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper holds
t1 is proper
let v, e be object ; for w being Vertex of G2
for G1 being addAdjVertex of G2,v,e,w
for t1 being TColoring of G1
for t2 being TColoring of G2
for x, y being object st not e in the_Edges_of G2 & not v in the_Vertices_of G2 & t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) & not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper holds
t1 is proper
let w be Vertex of G2; for G1 being addAdjVertex of G2,v,e,w
for t1 being TColoring of G1
for t2 being TColoring of G2
for x, y being object st not e in the_Edges_of G2 & not v in the_Vertices_of G2 & t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) & not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper holds
t1 is proper
let G1 be addAdjVertex of G2,v,e,w; for t1 being TColoring of G1
for t2 being TColoring of G2
for x, y being object st not e in the_Edges_of G2 & not v in the_Vertices_of G2 & t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) & not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper holds
t1 is proper
let t1 be TColoring of G1; for t2 being TColoring of G2
for x, y being object st not e in the_Edges_of G2 & not v in the_Vertices_of G2 & t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) & not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper holds
t1 is proper
let t2 be TColoring of G2; for x, y being object st not e in the_Edges_of G2 & not v in the_Vertices_of G2 & t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) & not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper holds
t1 is proper
let x, y be object ; ( not e in the_Edges_of G2 & not v in the_Vertices_of G2 & t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) & not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper implies t1 is proper )
assume that
A1:
( not e in the_Edges_of G2 & not v in the_Vertices_of G2 )
and
A2:
( t1 _V = (t2 _V) +* (v .--> x) & t1 _E = (t2 _E) +* (e .--> y) )
and
A3:
( not y in (rng (t2 _V)) \/ (rng (t2 _E)) & x <> y & x <> (t2 _V) . w & t2 is proper )
; t1 is proper
A4:
t1 _V is proper
by A1, A2, A3, Th23;
not y in rng (t2 _E)
by A3, XBOOLE_0:def 3;
then A5:
t1 _E is proper
by A1, A2, A3, Th94;
hence
t1 is proper
by A4, A5, Th146; verum