let G2 be _Graph; for v being object
for V being set
for G1 being addAdjVertexAll of G2,v,V
for v1 being Vertex of G1
for v2 being Vertex of G2 st v1 = v2 & not v2 in V holds
( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )
let v be object ; for V being set
for G1 being addAdjVertexAll of G2,v,V
for v1 being Vertex of G1
for v2 being Vertex of G2 st v1 = v2 & not v2 in V holds
( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )
let V be set ; for G1 being addAdjVertexAll of G2,v,V
for v1 being Vertex of G1
for v2 being Vertex of G2 st v1 = v2 & not v2 in V holds
( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )
let G1 be addAdjVertexAll of G2,v,V; for v1 being Vertex of G1
for v2 being Vertex of G2 st v1 = v2 & not v2 in V holds
( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )
let v1 be Vertex of G1; for v2 being Vertex of G2 st v1 = v2 & not v2 in V holds
( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )
let v2 be Vertex of G2; ( v1 = v2 & not v2 in V implies ( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() ) )
assume A1:
( v1 = v2 & not v2 in V )
; ( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )
per cases
( ( V c= the_Vertices_of G2 & not v in the_Vertices_of G2 ) or not V c= the_Vertices_of G2 or v in the_Vertices_of G2 )
;
suppose A2:
(
V c= the_Vertices_of G2 & not
v in the_Vertices_of G2 )
;
( v1 .edgesIn() = v2 .edgesIn() & v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )A3:
G2 is
Subgraph of
G1
by GLIB_006:57;
then A4:
v2 .edgesIn() c= v1 .edgesIn()
by A1, GLIB_000:78;
now for e being object st e in v1 .edgesIn() holds
e in v2 .edgesIn() let e be
object ;
( e in v1 .edgesIn() implies e in v2 .edgesIn() )A5:
e is
set
by TARSKI:1;
assume
e in v1 .edgesIn()
;
e in v2 .edgesIn() then consider x being
set such that A6:
e DJoins x,
v1,
G1
by GLIB_000:57;
A7:
x <> v
v1 <> v
by A1, A2;
then
e DJoins x,
v1,
G2
by A2, A6, A7, GLIB_007:def 4;
hence
e in v2 .edgesIn()
by A1, A5, GLIB_000:57;
verum end; then
v1 .edgesIn() c= v2 .edgesIn()
by TARSKI:def 3;
hence A8:
v1 .edgesIn() = v2 .edgesIn()
by A4, XBOOLE_0:def 10;
( v1 .inDegree() = v2 .inDegree() & v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )hence
v1 .inDegree() = v2 .inDegree()
;
( v1 .edgesOut() = v2 .edgesOut() & v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )A9:
v2 .edgesOut() c= v1 .edgesOut()
by A1, A3, GLIB_000:78;
now for e being object st e in v1 .edgesOut() holds
e in v2 .edgesOut() let e be
object ;
( e in v1 .edgesOut() implies e in v2 .edgesOut() )A10:
e is
set
by TARSKI:1;
assume
e in v1 .edgesOut()
;
e in v2 .edgesOut() then consider x being
set such that A11:
e DJoins v1,
x,
G1
by GLIB_000:59;
A12:
x <> v
v1 <> v
by A1, A2;
then
e DJoins v1,
x,
G2
by A2, A11, A12, GLIB_007:def 4;
hence
e in v2 .edgesOut()
by A1, A10, GLIB_000:59;
verum end; then
v1 .edgesOut() c= v2 .edgesOut()
by TARSKI:def 3;
hence A13:
v1 .edgesOut() = v2 .edgesOut()
by A9, XBOOLE_0:def 10;
( v1 .outDegree() = v2 .outDegree() & v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )hence
v1 .outDegree() = v2 .outDegree()
;
( v1 .edgesInOut() = v2 .edgesInOut() & v1 .degree() = v2 .degree() )thus
(
v1 .edgesInOut() = v2 .edgesInOut() &
v1 .degree() = v2 .degree() )
by A8, A13;
verum end; end;