yplusx = $yplusx; if ($yminusx === null) { $yminusx = new ParagonIE_Sodium_Core_Curve25519_Fe(); } $this->yminusx = $yminusx; if ($xy2d === null) { $xy2d = new ParagonIE_Sodium_Core_Curve25519_Fe(); } $this->xy2d = $xy2d; } }