theorem :: E_SIEC:26

for N being e_net holds
( (( the escape of N \ (id the carrier of N)) ~) * ((id ( the carrier of N \ (rng the escape of N))) ~) = ( the escape of N \ (id the carrier of N)) ~ & (( the entrance of N \ (id the carrier of N)) ~) * ((id ( the carrier of N \ (rng the entrance of N))) ~) = ( the entrance of N \ (id the carrier of N)) ~ )