Source: p 319, A Concise Introduction to Logic (12 Ed, 2014), by Patrick Hurley
in propositional logic it is usually simpler to equate “unless” with “or.”
In and using only ordinary English (and no Logic), how can 'unless' be interpreted to mean 'or'? Can semantic change explain how 'unless' = 'or'?
I wish to understand how 'unless' = 'or' directly and intuitively. So please do
not refer to or use the alternative (Stipulative) definition that 'unless' = 'if not'.
PS: I quoted the obsolete definition above, because I wish to understand 'unless' from first principles and because all the other definitions use some variant of 'if not'.