What is the order of operations for $p \implies q \implies r$ I've been studying mathematical logic recently and we have briefly covered the order of operations for operators like AND/OR/IMPLIES, etc.
However, we have a challenge question regarding how the following statement should be interpreted in terms of order of operations, and I don't believe we have covered this material nor can I find the same question answered online. 
The statement is
$p \implies q \implies r$
The question asks if the above statement is correctly represented by $(p \implies q) \implies r$, or $p \implies (q \implies r)$, or neither - i.e. what is the correct order of operations when there are no brackets and the two logic operators are equally weighted.
I have used a truth table to determine that the above two statements are not equivalent, but are either the logical equivalent to the first statement, or neither?

The answer for the purposes of your course (or if you were to see it in a paper specifically on logic) may be different, but in general mathematical usage this is shorthand for "$p\Rightarrow q$ and $q\Rightarrow r$", similar to constructs like $a\leq b\leq c$. 
(If something other than this is meant, I think parentheses should always be used.)
