begin
theorem Aux1: 
 for 
x, 
X being    
set   holds  not 
[x,X] in X
 
theorem Aux2: 
 for 
x, 
X being    
set   holds 
[x,X] <> X
 
theorem Aux3: 
 for 
x, 
X being    
set   holds 
[x,X] <> x
 
theorem Aux4: 
 for 
x1, 
y1, 
x2, 
y2, 
X being    
set   st 
x1 in X & 
x2 in X & 
{x1,[y1,X]} = {x2,[y2,X]} holds 
( 
x1 = x2 & 
y1 = y2 )
 
theorem card3: 
 for 
X, 
v being    
set   st 3 
c=  card X holds 
 ex 
v1, 
v2 being    
set  st 
( 
v1 in X & 
v2 in X & 
v1 <> v & 
v2 <> v & 
v1 <> v2 )
 
CSGLem1: 
 for X being    set  holds   union  {  V where V is   finite  Subset of X :  card V <= 2  }   = X
 
begin
Void0: 
 for n being   Nat holds  {{}} is n -at_most_dimensional 
 
CisSG: 
 for G being   SimpleGraph holds  (CompleteSGraph (Vertices G)) \ (Edges G) is   SimpleGraph
 
Compl1: 
 for G being   SimpleGraph holds   Vertices G =  Vertices ((CompleteSGraph (Vertices G)) \ (Edges G))
 
Compl1a: 
 for G being   SimpleGraph
  for x, y being    set   st x <> y & x in  Vertices G & y in  Vertices G holds 
( {x,y} in  Edges G iff {x,y} nin  Edges ((CompleteSGraph (Vertices G)) \ (Edges G)) )
 
Compl2: 
 for G, CG being   SimpleGraph  st CG = (CompleteSGraph (Vertices G)) \ (Edges G) holds 
(CompleteSGraph (Vertices CG)) \ (Edges CG) = G
 
begin
Sub1: 
 for G being   SimpleGraph
  for L, x being    set   st x in  Vertices (G SubgraphInducedBy L) holds 
x in L
 
Sub3: 
 for G being   SimpleGraph
  for L, x being    set   st x in L & x in  Vertices G holds 
x in  Vertices (G SubgraphInducedBy L)
 
Sub0c: 
 for G being   SimpleGraph
  for L being    set   st L c=  Vertices G holds 
 Vertices (G SubgraphInducedBy L) = L
 
Sub6: 
 for G being   SimpleGraph
  for L, x, y being    set   st x in L & y in L & {x,y} in G holds 
{x,y} in G SubgraphInducedBy L
 
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