While I am learning a lot from others here at the Computer Science site, I must admit that I don't get as much out of some questions and answers since I typically don't understand the theorems to the level necessary. I am currently reading How To Prove It - A Structured Approach which is starting to make the theorems easier to read, but still does not get me to the point of being able to understand the theorems to the point that they add great insight to the question or answer.
there is a use of a peroid in the premise.
$\qquad \displaystyle a \leq b \iff (a,b) \in E \lor \left(\exists\, c \in V. a \leq c \land c \leq b\right)$
What does the period mean? I would be expecting either a comma to mean conjuction or or to mean disjunction, but not a period. I don't see how this could be converted to logical statements.