let G3, G4 be _Graph; :: thesis: for v3 being Vertex of G3
for v4 being Vertex of G4
for e1, e2, v1, v2 being object
for G1 being addAdjVertex of G3,v3,e1,v1
for G2 being addAdjVertex of G4,v4,e2,v2
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 holds
ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )

let v3 be Vertex of G3; :: thesis: for v4 being Vertex of G4
for e1, e2, v1, v2 being object
for G1 being addAdjVertex of G3,v3,e1,v1
for G2 being addAdjVertex of G4,v4,e2,v2
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 holds
ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )

let v4 be Vertex of G4; :: thesis: for e1, e2, v1, v2 being object
for G1 being addAdjVertex of G3,v3,e1,v1
for G2 being addAdjVertex of G4,v4,e2,v2
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 holds
ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )

let e1, e2, v1, v2 be object ; :: thesis: for G1 being addAdjVertex of G3,v3,e1,v1
for G2 being addAdjVertex of G4,v4,e2,v2
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 holds
ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )

let G1 be addAdjVertex of G3,v3,e1,v1; :: thesis: for G2 being addAdjVertex of G4,v4,e2,v2
for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 holds
ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )

let G2 be addAdjVertex of G4,v4,e2,v2; :: thesis: for F0 being PGraphMapping of G3,G4 st not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 holds
ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )

let F0 be PGraphMapping of G3,G4; :: thesis: ( not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 implies ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) ) )

assume ( not e1 in the_Edges_of G3 & not e2 in the_Edges_of G4 & not v1 in the_Vertices_of G3 & not v2 in the_Vertices_of G4 & v3 in dom (F0 _V) & (F0 _V) . v3 = v4 ) ; :: thesis: ex F being PGraphMapping of G1,G2 st
( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )

then consider F being PGraphMapping of G1,G2 such that
A1: F = [((F0 _V) +* (v1 .--> v2)),((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 ) and
A5: ( F0 is directed implies F is directed ) by Th157;
take F ; :: thesis: ( F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] & ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )
thus F = [((F0 _V) +* (v1 .--> v2)),((F0 _E) +* (e1 .--> e2))] by A1; :: thesis: ( ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) & ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )
thus ( F0 is weak_SG-embedding implies F is weak_SG-embedding ) by A2, A4; :: thesis: ( ( F0 is isomorphism implies F is isomorphism ) & ( F0 is Disomorphism implies F is Disomorphism ) )
thus ( F0 is isomorphism implies F is isomorphism ) by A2, A3, A4; :: thesis: ( F0 is Disomorphism implies F is Disomorphism )
thus ( F0 is Disomorphism implies F is Disomorphism ) by A2, A3, A4, A5; :: thesis: verum