So I'm sitting in my logic grad course and the professor gives us this warm-up:

Determine whether the given argument is valid or invalid.

Premises: If I wash my car, then it will rain. It rained on Tuesday.

Conclusion: I washed my car on Tuesday.He then proceeded to ask us what the answer was. A few hands went up. He called on the overachieving soccer mom-type in the front row and she says it is valid. Professor then asks how many people agree. A few hands went up. He then says, "complete the Venn diagram for this problem for the next class meeting." The WHOLE time, I'm thinking, "What is everyone talking about??" And the book has been no help, bc it assumes I know what all the symbols stand for. I've never taken a math class anywhere near this level.

Can anyone please explain how to solve this problem??