a=b ∨ a=c ∨ b=c = T
I have expanded the LHS as follows. But have no clue how to continue from there
(a=>b)∧(b=>a) ∨ (a=>c)∧(c=>a) ∨ (b=>c)∧(c=>b)
Link for the question [Q (p)]. http://www.cs.utoronto.ca/~hehner/aPToP/solutions/Ex6.pdf
The solution is not understood.
Lets say without loss of generality that $a<=>b$. Then, a and b are both true or both false, which means that $a=>b$ and $b=>a$.