let n, k be Element of NAT ; ( min* {n,k} = min (n,k) & min {n,k} = min (n,k) )
A1:
min {n} = n
by Th5;
{n,k} = {n} \/ {k}
by ENUMSET1:1;
then A2:
min {n,k} = min ((min {n}),(min {k}))
by Th2;
min {n,k} = min* {n,k}
by Th1;
hence
( min* {n,k} = min (n,k) & min {n,k} = min (n,k) )
by A2, A1, Th5; verum