Your search - ∏ - did not match any documents.Luckily, I stumbled upon this page which briefly explains, and gives names for, these notations. For example: "|-" means "entails", "<:" is a subtype relation, ⊥ is "bottom", its inverse Τ is "top", Γ is "context", and the long horizontal line is sort of an if-then statement:
"if everything above the bar (the premises) is true, then the thing below the bar (the conclusion) is true"Excellent, this will be very helpful when I encounter another one of these papers. I wish computer scientists understood that their notation is far from universally known and that, without a "legend" or informative URL, mere computer engineers like me not only cannot understand the notation, but cannot learn about it either.
Update: here's a more detailed introduction to Programming Language Theory.