let F1, F2 be Function of (thin_cylinders A1,B1),(thin_cylinders A2,B2); :: thesis: ( ( for x being set st x in thin_cylinders A1,B1 holds
ex Bo being Subset of B1 ex yo1 being Function of Bo,A1 ex yo2 being Function of Bo,A2 st
( Bo is finite & yo1 = yo2 & x = cylinder0 A1,B1,Bo,yo1 & F1 . x = cylinder0 A2,B2,Bo,yo2 ) ) & ( for x being set st x in thin_cylinders A1,B1 holds
ex Bo being Subset of B1 ex yo1 being Function of Bo,A1 ex yo2 being Function of Bo,A2 st
( Bo is finite & yo1 = yo2 & x = cylinder0 A1,B1,Bo,yo1 & F2 . x = cylinder0 A2,B2,Bo,yo2 ) ) implies F1 = F2 )

assume AS1: for x being set st x in thin_cylinders A1,B1 holds
ex Bo being Subset of B1 ex yo1 being Function of Bo,A1 ex yo2 being Function of Bo,A2 st
( Bo is finite & yo1 = yo2 & x = cylinder0 A1,B1,Bo,yo1 & F1 . x = cylinder0 A2,B2,Bo,yo2 ) ; :: thesis: ( ex x being set st
( x in thin_cylinders A1,B1 & ( for Bo being Subset of B1
for yo1 being Function of Bo,A1
for yo2 being Function of Bo,A2 holds
( not Bo is finite or not yo1 = yo2 or not x = cylinder0 A1,B1,Bo,yo1 or not F2 . x = cylinder0 A2,B2,Bo,yo2 ) ) ) or F1 = F2 )

assume AS2: for x being set st x in thin_cylinders A1,B1 holds
ex Bo being Subset of B1 ex yo1 being Function of Bo,A1 ex yo2 being Function of Bo,A2 st
( Bo is finite & yo1 = yo2 & x = cylinder0 A1,B1,Bo,yo1 & F2 . x = cylinder0 A2,B2,Bo,yo2 ) ; :: thesis: F1 = F2
now
let x be set ; :: thesis: ( x in thin_cylinders A1,B1 implies F1 . x = F2 . x )
assume AS3: x in thin_cylinders A1,B1 ; :: thesis: F1 . x = F2 . x
consider Bo1 being Subset of B1, yo11 being Function of Bo1,A1, yo21 being Function of Bo1,A2 such that
P1: ( Bo1 is finite & yo11 = yo21 & x = cylinder0 A1,B1,Bo1,yo11 & F1 . x = cylinder0 A2,B2,Bo1,yo21 ) by AS3, AS1;
consider Bo2 being Subset of B1, yo12 being Function of Bo2,A1, yo22 being Function of Bo2,A2 such that
P2: ( Bo2 is finite & yo12 = yo22 & x = cylinder0 A1,B1,Bo2,yo12 & F2 . x = cylinder0 A2,B2,Bo2,yo22 ) by AS3, AS2;
P3: ( Bo1 = Bo2 & yo11 = yo12 ) by LM3, P1, P2;
thus F1 . x = F2 . x by P1, P2, P3; :: thesis: verum
end;
hence F1 = F2 by FUNCT_2:18; :: thesis: verum