Let M and N be two$$$-$NFA$$s such that: $1)$ M has a single final state, not equal to its start state, with no transitions out of it$,$ and $2)$ N$$s start state is non$-$final and has no transitions into it$.$ Let O be the$$$-$NFA obtained by merging the final state of M with the start state of N$,$ and making it non$-$final. Then L$($O$)=$ L$($M$)$L$($N$).$