Background
The E Electric Company emits smoke, which dirties the wash at the L Laundry. ▶ E can abate this external cost by installing scrubbers on its stacks, and L can reduce the damage by installing filters on its ventilation system. ▶ When E does not install scrubbers, its profits are 300. ▶ Pollution destroys 100, or E can avoid it by installing scrubbers at a cost of $500.
So we can conclude a Nash Equilibrium table: