let x1, x2, x3, x5, x6, x7 be non pair set ; :: thesis: InputVertices (STC0IIStr (x1,x2,x3,x5,x6,x7)) = {x1,x2,x3,x5,x6,x7}
set S = STC0IIStr (x1,x2,x3,x5,x6,x7);
set S1 = BitGFA0Str (x1,x2,x3);
set S2 = BitGFA0Str (x5,x6,x7);
A1: ( InputVertices (BitGFA0Str (x1,x2,x3)) = {x1,x2,x3} & InputVertices (BitGFA0Str (x5,x6,x7)) = {x5,x6,x7} ) by GFACIRC1:34;
( InnerVertices (BitGFA0Str (x1,x2,x3)) is Relation & InnerVertices (BitGFA0Str (x5,x6,x7)) is Relation ) ;
hence InputVertices (STC0IIStr (x1,x2,x3,x5,x6,x7)) = {x1,x2,x3} \/ {x5,x6,x7} by A1, FACIRC_1:7
.= {x1,x2,x3,x5,x6,x7} by ENUMSET1:13 ;
:: thesis: verum