Consider a theorem of a form $\ A\Rightarrow T.\ $ Consider two proofs: Proof 1: $$ A\Rightarrow C\qquad\mbox{and} \qquad C\Rightarrow T $$ Proof 2: $$ A\Rightarrow \Gamma\qquad\mbox{and}\qquad \Gamma\Rightarrow T $$ If also another theorem is true: $$ \neg(C\Rightarrow\Gamma) $$ then -- objectively -- Proof 1 and Proof 2 are not equivalent. And if someone provided proof of the last-mentioned theorem then Proof 1 and Proof 2 would be explicitly not equivalent. >Thus every explicit equivalence is objective but the inverse depends on the status of the last-mentioned theorem.