Some gardening books published by Garden Path Press recommend tilling the soil and adding compost before starting a new garden on a site, but they do not explain the difference between hot and cold composting.
Evidence
Some gardening books published by Garden Path Press recommend tilling the soil and adding compost before starting a new garden on a site.
The gardening books by Garden Path Press do not explain the difference between hot and cold composting.
Any gardening book that recommends adding compost is flawed if it does not explain at least the basics of composting.
Conclusion
Some books published by Garden Path are flawed.
Evaluate
The author's conclusion is trying to prove that some books from GP are flawed, and we were given a proving-mechanism that allows us to prove something is flawed.
If it recommends adding compost but don't explain at least the basics of composting, then it's flawed.
Did the evidence establish that some GP books recommend adding compost but don't cover the basics of composting?
Not quite. We heard that some GP books recommend adding compost. We never heard that the books fail to cover the basics of composting.
We only heard that the books fail to explain the difference between hot and cold composting.
Goal
So, the author seems to be assuming that .
Or alternatively, .