-Hence, we can define <code>(φ -v- η)[x]</code> as: <code>φ[x] ∘ η[x]</code> and rely on it to satisfy the constraints for a natural transformation from `G` to `J`:
+Hence, we can define <code>(φ -v- η)[\_]</code> as: <code>φ[\_] ∘ η[\_]</code> and rely on it to satisfy the constraints for a natural transformation from `G` to `J`: