Source: p 67. Exercise 3.6.7. Sweet Reason: A Field Guide to Modern Logic (2010 2 ed) by Henle, Garfield, Tymoczko.
Design a circuit to function in the same way as each statement.
7. P ∨ ¬P (Is the result what you would expect?)
When I attempted this exercise, I drew the red distinct line, without the green line. But why is the green correct and necessary, and the red wrong?