3 ms·

From my reading, it looks like can't make up their mind about whether Q = {X . Y: X, Y graphs} or Q = {X . Y : X, Y in Q}. Neither definitions seems to work eve

From my reading, it looks like can't make up their mind about whether Q = {X . Y: X, Y graphs} or Q = {X . Y : X, Y in Q}. Neither definitions seems to work everywhere.

srcreigh 4y ago
Where does Q = { (S1 . T1) . (S2 . T2) : S1,S2,T1,T2 in Q } not work?
- isaacg 4y ago
  This definition fails because Q-bar needs to be a subset of Q, but in Q-bar, the graphs T1, S2, and T2 are specified to be the single-edge graphs e1, e2, e3. But single-edge graphs are not in Q.