25. Because the only question we are concerned with is whether the Conclusion follows logically from the Premisses, so that, if they were true, it also would be true.
26. By understanding a red counter to mean "this compartment can be occupied", and a grey one to mean "this compartment cannot be occupied" or "this compartment must be empty".
27. 'Fallacious Premisses' and 'Fallacious Conclusion'.
28. By finding, when we try to transfer marks from the larger Diagram to the smaller, that there is 'no information' for any of its four compartments.
29. By finding the correct Conclusion, and then observing that the Conclusion, offered to us, is neither identical with it nor a part of it.
30. When the offered Conclusion is part of the correct Conclusion. In this case, we may call it a 'Defective Conclusion'.
§ 2. Half of Smaller Diagram.
[See pp. 39, 40]