(no subject)

[timelets]

Two logics are “the same” if and only if they are equivalent as preorders.
...

Observe that both logics can use the same set A of statements, but the consequence relation is different for the two.

--- Lutz Straßburger. What is a logic, and what is a proof?, 2006

The concept of "consequences relation" is key to understanding misunderstandings.

Comments

[juan_gandhi]

Interesting! I somehow had skipped that part.