Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Parser.php
private function condition()
    {
        $result = $this->expression();
        if ($this->currentToken == '<') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgLT', $result, $result2);
        } elseif ($this->currentToken == '>') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgGT', $result, $result2);
        } elseif ($this->currentToken == '<=') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgLE', $result, $result2);
        } elseif ($this->currentToken == '>=') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgGE', $result, $result2);
        } elseif ($this->currentToken == '=') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgEQ', $result, $result2);
        } elseif ($this->currentToken == '<>') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgNE', $result, $result2);
        } elseif ($this->currentToken == '&') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgConcat', $result, $result2);
        }

        return $result;
    }
private function condition()
    {
        $result = $this->expression();
        if ($this->currentToken == '<') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgLT', $result, $result2);
        } elseif ($this->currentToken == '>') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgGT', $result, $result2);
        } elseif ($this->currentToken == '<=') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgLE', $result, $result2);
        } elseif ($this->currentToken == '>=') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgGE', $result, $result2);
        } elseif ($this->currentToken == '=') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgEQ', $result, $result2);
        } elseif ($this->currentToken == '<>') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgNE', $result, $result2);
        } elseif ($this->currentToken == '&') {
            $this->advance();
            $result2 = $this->expression();
            $result = $this->createTree('ptgConcat', $result, $result2);
        }

        return $result;
    }
It parses a condition. It assumes the following rule:
Cond -> Expr [(">" | "<") Expr].

@return mixed The parsed ptg'd tree on success