If it has rained, the ground is damp;
It has not rained,
Therefore the ground is not damp.
(3) Minor premise affirms consequent.
If it has rained, the ground is damp;
The ground is damp,
Therefore it has rained.
(4) Minor premise denies the consequent.
If it has rained, the ground is damp;
The ground is not damp,