Propositional logic: Proof question (p∧q)→r⊢(p→q)→r Am I correct to assume that there is no proof for $$(p∧q)→r ⊢ (p→q)→r$$ 
I´ve spent hours trying to figure it out, by now I suspect there might have been a mistake in the exercise. I have been able to proof
$$(p∧q)→r ⊢ p→(q→r)$$ (using Fitch notation), so it seems unlikely to me that 
$$(p∧q)→r ⊢ (p→q)→r$$ is valid as well. I´m quite new to propositional logic, so I just wanted to ask whether my reasoning is sound!

There is no proof because the tableau of $\lnot (((p\land q)\to r)\to ((p\to q)\to r)))$ is not closed.
