since the experimenter cannot see inside the box while it is closed, opening the box is done with no knowledge of what has happened within the interior I of the box. If we take the interactions necessary to open the box to be captured by ˆ G$_{B}$ , then this must commute with ˆ G$_{I}$ determined above. Now, opening the box is a macroscopic, classical act which can be presumed to either happen (with probability 1) or not. Whether the box is opened can thus be considered to be fully determined by the initial state, which includes the intention of the experimenter whether to open the box or not. Suppose in the initial state | Ψ$_{I}$ 〉 0 the experimenter does, in fact, open the box some time within the hypervolume B ∪ I . Then Once the box is open, the interior of the box can interact with the environment and it becomes known in the environment whether the cat is alive or dead in the interior of the box. So Thus, using Eq. (41), where the environment records whether the cat is alive or dead. However, now assume a different initial state | Ψ ′ I 〉 0 that is the same as | Ψ$_{I}$ 〉 0 except that it does not lead to the experimenter opening the box during the time period covered by V . In this case and, with the box closed, the interior cannot interact with the environment: The change in initial state does not effect what happens in the interior of the box, so, using Eq. (41) again, 27 ˆ G$_{V}$ | Ψ ′ I 〉 0 = ˆ P closed E ˆ G$_{E}$ ˆ P closed B ˆ G$_{B}$ ( ˆ P alive C + ˆ P dead C ) ˆ G$_{I}$ | Ψ ′ I 〉 0 = ˆ P closed E ˆ G$_{E}$ ˆ P closed B ( ψ no R | r $^{no}$, d$^{no}$, c$^{alive}$〉 0 + ψ yes R | r $^{yes}$, d$^{yes}$, c$^{dead}$〉$_{0}$) = ψ no R | r $^{no}$, d$^{no}$, c$^{alive}$, b$^{closed}$, e$^{closed}$〉 0 + ψ yes R | r $^{yes}$, d$^{yes}$, c$^{dead}$, b$^{closed}$, e$^{closed}$〉$_{0}$. (42) ˆ G$_{V}$ | Ψ ′ I 〉 0 = ˆ G$_{E}$ ˆ G$_{B}$ ˆ G$_{I}$ | Ψ ′ I 〉 0 = ˆ P closed E ˆ G$_{E}$ ˆ P closed B ˆ G$_{B}$ ˆ G$_{I}$ | Ψ ′ I 〉 0 ˆ G$_{B}$ ˆ G$_{I}$ | Ψ ′ I 〉 0 = ˆ P closed B ˆ G$_{B}$ ˆ G$_{I}$ | Ψ ′ I 〉 $_{0}$. ˆ G$_{V}$ | Ψ$_{I}$ 〉 0 = ˆ P alive E ˆ G$_{E}$ ˆ P open B ˆ G$_{B}$ψ no R | r $^{no}$, d$^{no}$, c$^{alive}$〉 0 + ˆ P dead E ˆ G$_{E}$ ˆ P open B ˆ G$_{B}$ψ yes R | r $^{yes}$, d$^{yes}$, c$^{dead}$〉 = ψ no R | r $^{no}$, d$^{no}$, c$^{alive}$, b$^{open}$, e$^{alive}$〉 0 + ψ yes R | r $^{yes}$, d$^{yes}$, c$^{dead}$, b$^{open}$, e$^{dead}$〉$_{0}$, ˆ G$_{V}$ | Ψ$_{I}$ 〉 0 = ˆ G$_{E}$ ˆ G$_{B}$ ˆ G$_{I}$ | Ψ$_{I}$ 〉 0 = ˆ G$_{E}$ ˆ P open B ˆ G$_{B}$ ˆ G$_{I}$ | Ψ$_{I}$ 〉 0 = ˆ P alive E ˆ G$_{E}$ ˆ P open B ˆ G$_{B}$ ˆ P alive C ˆ G$_{I}$ | Ψ$_{I}$ 〉 0 + ˆ P dead E ˆ G$_{E}$ ˆ P open B ˆ G$_{B}$ ˆ P dead C ˆ G$_{I}$ | Ψ$_{I}$ 〉 $_{0}$. ˆ G$_{B}$ ˆ G$_{I}$ | Ψ$_{I}$ 〉 0 = ˆ G$_{I}$ ˆ G$_{B}$ | Ψ$_{I}$ 〉 0 = ˆ G$_{I}$ ˆ P open B ˆ G$_{B}$ | Ψ$_{I}$ 〉 0 = ˆ P open B ˆ G$_{B}$ ˆ G$_{I}$ | Ψ$_{I}$ 〉 $_{0}$.