Prof Bulani wrote:Terrapin, just try it yourself.
X = X is true
~X = X cannot possibly be true
X < X cannot possibly be true
Try X = 4, X = "apple pie", X = "pineapple on pizza is delicious". Try other values of X
So the logical operator '=' is equivalent to the English words "is" and "equals" isn't it?
Now you're happy that it would be logically self-contradictory to say "~X = X" or "An apple is not an apple" (what a surprise!) can you find any examples of anybody actually claiming anything different?
RJG, over and over again, re-states the above three obvious logical truths, almost as if somebody somewhere has denied them. Can you see a purpose in doing that? Coz I can't. Except, of course, for the purpose of constructing an argument against a position that has not been taken by anybody, because it's easier than constructing an argument against a position that somebody has, actually, taken. (That's often referred to as a "straw man" technique, where the metaphorical "straw man" is the constructed position being attacked.)