No short kangaroos who are smart will go driving.
The proof of this is as follows:
Assume that he will go driving.
- A short creature who goes driving will have sneezing fits.
- A smart creature who has sneezing fits will not dance on tight-ropes.
- A short creature who does not dance on tight-ropes must eat peanut butter.
- Also, a kangaroo who has sneezing fits will be avoided.
- A creature who is avoided and who does not dance on tight-ropes must have spikey hair.
- A smart driver wears sunglasses.
- A kangaroo wearing sunglasses looks silly.
- A silly creature who eats peanut butter and is smart will not go swimming.
- However, a creature with spikey hair who looks silly and does not dance on tight-ropes will go swimming.
Here, we have a contradiction; the same creature will not go swimming and will go swimming, so the assumption that the kangaroo in question can drive must be false.