let G3, G4 be _Graph; for v1, v3 being Vertex of G3
for v2, v4 being Vertex of G4
for e1, e2 being object
for G1 being addEdge of G3,v1,e1,v3
for G2 being addEdge of G4,v2,e2,v4
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) holds
ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
let v1, v3 be Vertex of G3; for v2, v4 being Vertex of G4
for e1, e2 being object
for G1 being addEdge of G3,v1,e1,v3
for G2 being addEdge of G4,v2,e2,v4
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) holds
ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
let v2, v4 be Vertex of G4; for e1, e2 being object
for G1 being addEdge of G3,v1,e1,v3
for G2 being addEdge of G4,v2,e2,v4
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) holds
ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
let e1, e2 be object ; for G1 being addEdge of G3,v1,e1,v3
for G2 being addEdge of G4,v2,e2,v4
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) holds
ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
let G1 be addEdge of G3,v1,e1,v3; for G2 being addEdge of G4,v2,e2,v4
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) holds
ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
let G2 be addEdge of G4,v2,e2,v4; for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) holds
ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
let F0 be PGraphMapping of G3,G4; ( not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) implies ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) ) )
assume
( not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & v1 in dom (F0 _V) & v3 in dom (F0 _V) & ( ( (F0 _V) . v1 = v2 & (F0 _V) . v3 = v4 ) or ( (F0 _V) . v1 = v4 & (F0 _V) . v3 = v2 ) ) )
; ex F being PGraphMapping of G1,G2 st
( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
then consider F being PGraphMapping of G1,G2 such that
A1:
F = [(F0 _V),((F0 _E) +* (e1 .--> e2))]
and
A2:
( F0 is total implies F is total )
and
A3:
( F0 is onto implies F is onto )
and
A4:
( F0 is one-to-one implies F is one-to-one )
by Th152;
take
F
; ( F = [(F0 _V),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
thus
F = [(F0 _V),((F0 _E) +* (e1 .--> e2))]
by A1; ( ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) )
thus
( F0 is weak_SG-embedding implies F is weak_SG-embedding )
by A2, A4; ( F0 is isomorphism implies F is isomorphism )
thus
( F0 is isomorphism implies F is isomorphism )
by A2, A3, A4; verum