leftExpr; } public function getOperator(): string { return $this->operator; } public function getRightExpr(): mixed { return $this->rightExpr; } public function __toString(): string { // Adjusting Left Expression $leftExpr = (string) $this->leftExpr; if ($this->leftExpr instanceof Math) { $leftExpr = '(' . $leftExpr . ')'; } // Adjusting Right Expression $rightExpr = (string) $this->rightExpr; if ($this->rightExpr instanceof Math) { $rightExpr = '(' . $rightExpr . ')'; } return $leftExpr . ' ' . $this->operator . ' ' . $rightExpr; } }