consider G being _Graph;
set F = NAT --> G;
A1: dom (NAT --> G) = NAT by FUNCOP_1:19;
reconsider F = NAT --> G as ManySortedSet of NAT ;
take F ; :: thesis: F is Graph-yielding
let x be Nat; :: according to GLIB_000:def 55 :: thesis: F . x is _Graph
x in NAT by ORDINAL1:def 13;
then F . x in rng F by A1, FUNCT_1:12;
then F . x in {G} by FUNCOP_1:14;
hence F . x is _Graph by TARSKI:def 1; :: thesis: verum