let x, y, c be non pair set ; :: thesis: for s being State of (BorrowCirc (x,y,c))
for a2, a3 being Element of BOOLEAN st a2 = s . y & a3 = s . c holds
(Following (s,2)) . [<*y,c*>,and2] = a2 '&' a3
reconsider a = x as Vertex of (BorrowStr (x,y,c)) by Th6;
let s be State of (BorrowCirc (x,y,c)); :: thesis: for a2, a3 being Element of BOOLEAN st a2 = s . y & a3 = s . c holds
(Following (s,2)) . [<*y,c*>,and2] = a2 '&' a3
s . a is Element of BOOLEAN ;
hence for a2, a3 being Element of BOOLEAN st a2 = s . y & a3 = s . c holds
(Following (s,2)) . [<*y,c*>,and2] = a2 '&' a3 by Lm2; :: thesis: verum