Some logical statements are “the same.” For example, we discussed the fact that a conditional and its contrapositive have the same logical content. However, the equals sign (=) has already got a job...Some logical statements are “the same.” For example, we discussed the fact that a conditional and its contrapositive have the same logical content. However, the equals sign (=) has already got a job; it is used to indicate that two numerical quantities are the same. The formal definition of logical equivalence is two compound sentences are logically equivalent if in a truth table, the truth values of the two sentences are equal in every row. Thus, we use the symbol (≅) instead.